MARIO DONINELLI WITH RADIANT PANELS SYSTEMS · buildings, thus achieving the first central-heating type system. However, it was not until the start of this century that underfloor

MARIO DONINELLI

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SYSTEMS WITH RADIANT PANELS

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MARIO DONINELLI

SYSTEMSWITH RADIANT PANELS

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INTRODUCTION

This radiant panel equipment Handbook comes out at the same time as the manifoldssystem Handbook.

First of all (ie. with the third Handbook), we considered that we should focus ourattention on manifold systems, as these are the most popular at present and aretherefore of greater design interest. However, we did not wish to delay thepresentation of panel systems excessively.In fact, we consider that these systems are now likely to extend to Italy thedistribution and success they have achieved - and are still achieving - in thetechnologically more advanced countries of Northern Europe.We also consider that their distribution and success can be assisted by clear,thorough information which is easy to understand. And this is the spirit in which wehave tried to provide our contribution.

As amply illustrated in this Handbook, there is no longer any reason to doubt thevalidity of panel systems, and it is therefore important to look at these withoutprejudice and with careful attention.Knowing how to design and produce these systems in fact makes it possible tocomplete and qualify the range on offer. And this is most important, in a sector likeours, where everything changes very quickly and one can no longer stay tuckedaway in a cosy niche market.There is a continuous need to learn; we must know how to adapt to therequirements of a continuously changing world. Only in this way can we offertechnologically advanced solutions, which are competitive and thus able to meetour clients’reasonable demands.

Finally, I should like to express my warmest thanks to the Author of this publicationand all those who have contributed to writing it.As always, any suggestions, opinions and impressions will be very welcome.

Franco CaleffiChairman, CALEFFI, S.p.A.

This Handbook offers an analysis of the main aspects of the performance,production and design of floor-mounted (under-floor) radiant panel equipment. Thisanalysis is broken down into three parts.

1) Initially, the aspects inherent in the heating performance of the systems will beexamined, followed by the materials, control systems and implementationtechniques with which they are normally produced.For their dimensioning, a method of calculation derived from European Standard EN 1264 is proposed.

2) Next, the general structure of the calculation programme is illustrated, with therelevant options and command functions.The programme provides for stand-alone dimensioning of each panel. In otherwords, it provides for a procedure which varies considerably in relation to that usedfor manifold systems, where all the branch circuits (from the manifold itself) aredimensioned at the same time.This difference is due to the fact that in systems with manifolds, the heatingdimensioning is based on variables which depend only on the individual heatemitters, their construction characteristics and the temperature of the fluid.Unlike these, in panel systems, the “heating surfaces“ are also dimensioned on thebasis of variables which depend on the specific nature of the area to be served.This makes methods based on automatic, generalised choices highly complex andnot always reliable.

3) Finally, an example will be given in order to assist in the use of the programmeand give information on how to select the main project variables.

You don’t have to read the whole manual to be able to use the calculationprogramme. In particular, the chapters on panel dimensioning can be omitted or leftuntil later. The essential purpose of these chapters is in fact to illustrate the formulaeand procedures on which the operation of the programme is based.

I should like to thank Marco Doninelli and Claudio Ardizzoia for their constant hard work.Finally, I should also like to thank Caleffi for giving me the opportunity to completethis task.

Mario Doninelli

PREFACE

N O T E S

GENERAL STRUCTURE

Definitions, graphs, tables, formulae, command functions, examples and advice aregiven under items (or headings).

Each item, while forming part of the general context, can, in practice, stand alone.The connections between items are indicated by appropriate referrals: each referral isclearly shown in rounded brackets.

Graphs, tables and formulae have consecutive numbering linked only to the contextof the item in which they are contained. Longer items, sometimes introduced by ashort contents list, are broken down into chapters and sub-chapters.

DRAWINGS AND DIAGRAMS

The items are supplemented by drawings and diagrams which illustrate the essentialfunctional aspects of the systems, equipment and details described. No installationdrawings are enclosed.

SIGNS, SYMBOLS AND ABBREVIATIONS

Signs and symbols (relating to mathematics, physics, chemistry, etc.) are those incurrent use. As far as possible, the use of abbreviations has been avoided; those whichare used are specified in each case.

UNITS OF MEASUREMENT

The International System has not been rigidly applied. Traditional technical units ofmeasurement have sometimes been used instead, as:

1. they are more immediate and understandable from the practical point of view;

2. they are the actual units of measurement referred to in the working language ofthe technicians and fitters.

GREEK ALPHABET

Physical sizes, numeric coefficients and constants are often represented by letters ofthe Greek alphabet. These letters are shown below with their pronunciation.

Let t e r s o f the Greek A lphabe t

Upper Case Lower Case Name Upper Case Lower Case Name

Α α alpha Ν ν nu

Β β beta Ξ ξ xi

Γ γ gamma Ο ο omicron

∆ δ delta Π π pi

Ε ε epsilon Ρ ρ rho

Ζ ζ zeta Σ σ sigma

Η η eta Τ τ tau

Θ θ theta Υ υ upsilon

Ι ι iota Φ φ phi

Κ κ kappa Χ χ chi

Λ λ lambda Ψ ψ psi

Μ µ mu Ω ω omega

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N O T E S

HISTORIC BACKGROUND..................................................................................................................... 4ADVANTAGES OF PANEL SYSTEMS .................................................................................................... 6

- THERMAL WELL-BEING .................................................................................................................................. 6- AIR QUALITY .................................................................................................................................................... 8- HEALTH CONDITIONS .................................................................................................................................... 8- ENVIRONMENTAL IMPACT ........................................................................................................................... 8- HEAT USABLE AT LOW TEMPERATURE ...................................................................................................... 9- ENERGY SAVING ............................................................................................................................................. 9

LIMITATIONS AND DISADVANTAGES OF PANEL SYSTEMS ............................................................. 10- LIMITATIONS CONNECTED WITH THE SURFACE TEMPERATURE OF THE FLOOR ............................ 10- THERMAL INERTIA AND METHOD OF USE OF SYSTEMS ......................................................................... 10- DISADVANTAGES CONNECTED WITH DESIGN ASPECTS ........................................................................ 11

COOLING OF ROOMS ............................................................................................................................. 11COST OF PRODUCTION AND MANAGEMENT .................................................................................... 12APPLICATIONS ..................................................................................................................................... 12

PANEL CONTAINMENT STRUCTURES ........................................................................................................... 14- INSULATING MATERIALS ............................................................................................................................... 15- PERIPHERAL JOINTS ....................................................................................................................................... 16- MAIN JOINTS .................................................................................................................................................... 16- EDGE JOINTS .................................................................................................................................................... 17- SLAB .................................................................................................................................................................... 17- FLOORS .............................................................................................................................................................. 17

DISTRIBUTION OF HEAT-CARRYING FLUID .............................................................................................. 18 - MANIFOLDS ....................................................................................................................................................... 18- PANELS ............................................................................................................................................................... 19

PRESSURE TEST AND START-UP ..................................................................................................................... 23

Part one

GENERAL NOTES AND METHODS OF CALCULATION

GENERAL NOTES Page 3

CONSTRUCTION OF RADIANT PANEL SYSTEMS Page 13

C O N T E N T S

CALCULATION PARAMETERS .............................................................................................................. 34UPWARD HEAT FLOW FROM A PANEL .............................................................................................. 36

- LOGARITHMIC MEAN BETWEEN FLUID TEMPERATURE AND AMBIENT TEMPERATURE ............... 37- FACTORS RELATING TO PIPE CHARACTERISTICS ..................................................................................... 38- FACTORS RELATING TO THERMAL RESISTANCE OF FLOOR ................................................................... 39- FACTORS RELATING TO CENTRE-TO-CENTRE DISTANCE OF PIPES ..................................................... 40- FACTORS RELATING TO THICKNESS OF SLAB ABOVE PIPES ................................................................. 41- FACTORS RELATING TO OUTER DIAMETER OF PIPE ............................................................................... 42

TOTAL HEAT EMISSION FROM A PANEL ............................................................................................ 43

CALCULATION OF PANELS ............................................................................................................................... 45PARAMETERS REQUIRED .................................................................................................................................. 50

- CENTRE-TO-CENTRE DISTANCES ................................................................................................................. 50- PRESET HEAD ................................................................................................................................................... 51- MAX. DESIGN TEMPERATURE ...................................................................................................................... 51- HEAT OUTPUT REQUIRED ............................................................................................................................. 52- AMBIENT TEMPERATURE .............................................................................................................................. 52- TEMPERATURE OF ROOM OR GROUND BELOW ...................................................................................... 53- THERMAL RESISTANCE OF FLOOR ............................................................................................................... 54- THERMAL RESISTANCE UNDER PANEL ...................................................................................................... 58

PARAMETERS TO BE DETERMINED ................................................................................................................ 62- SURFACE TEMPERATURE OF FLOOR ............................................................................................................ 62- TEMPERATURE DIFFERENCE OF HEATING FLUID .................................................................................... 64- FLOW IN PANEL ............................................................................................................................................... 64- HEAD REQUIRED ............................................................................................................................................. 65- LENGTH OF PANEL .......................................................................................................................................... 65- FLUID VELOCITY .............................................................................................................................................. 66- TOTAL HEAT OUTPUT EMITTED BY PANEL ............................................................................................... 66- HEAT OUTPUT EMITTED DOWNWARDS .................................................................................................... 66- MEAN HEAT OUTPUT EMITTED UPWARDS BY ONE METRE OF PIPE ................................................... 66- MEAN HEAT OUTPUT EMITTED DOWNWARDS BY ONE METRE OF PIPE ........................................... 66

CONTROL SYSTEMS Page 24

HEAT FLOW EMITTED BY A PANEL Page 33

DIMENSIONING OF PANELS Page 44

ZONE VALVE ARCHIVE ...................................................................................................................................... 70ARCHIVE OF VALVES FOR HEAT EMITTERS ................................................................................................ 72 HEAT EMITTERS ARCHIVE ............................................................................................................................... 74

MAIN PARAMETERS ARCHIVE ......................................................................................................................... 78MANIFOLD DATA ARCHIVE ............................................................................................................................. 80 DATA ARCHIVE FOR PIPES AND CENTRE DISTANCES ............................................................................. 81

MANIFOLD MANAGEMENT AND PROCESS PRINTING ...................................................................... 84BRANCH CIRCUITS MANAGEMENT .................................................................................................... 85PANEL DIMENSIONING ........................................................................................................................ 86

- ACQUISITION OF PROJECT DATA ................................................................................................................ 86- DEVELOPMENT OF CALCULATIONS ............................................................................................................. 88- PRESENTATION OF THE DATA PROCESSED ............................................................................................... 89

CALCULATION OF HEAT EMITTERS .................................................................................................... 90- ACQUISITION OF PROJECT DATA ................................................................................................................ 90- DEVELOPMENT OF CALCULATIONS ............................................................................................................. 91- PRESENTATION OF THE DATA PROCESSED ............................................................................................... 91

SELECTION OF SOLUTIONS PROCESSED ............................................................................................. 92

PRINTER CONFIGURATION Page 68

MATERIALS ARCHIVES Page 69

GENERAL DATA ARCHIVES Page 77

PROJECT ARCHIVE MANAGEMENT Page 82

CALCULATION PROGRAMME Page 83

Part two

PROGRAMME FOR THE DIMENSIONINGOF SYSTEMS WITH PANELS

EXAMPLE OF CALCULATION USING CALEFFI SOFTWARE ............................................................... 94- ANALYSIS AND SELECTION OF MAIN PARAMETERS ................................................................................ 96- SELECTION OF MANIFOLDS AND VALVES ................................................................................................... 100- SELECTION OF PIPE AND CENTRE-TO-CENTRE DISTANCES ................................................................... 100- NOTES AND CONVENTIONS USED ............................................................................................................... 101- ACTIVATION OF PROJECT FILE ..................................................................................................................... 102- DIMENSIONING BRANCHES .......................................................................................................................... 103- PRINT-OUT AND SYMBOLS ............................................................................................................................ 128- DIMENSIONING THE DISTRIBUTION NETWORK ..................................................................................... 130- CALCULATION OF TOTAL HEAT OUTPUT .................................................................................................. 130

BIBLIOGRAPHY Page 136

Part three

EXAMPLE OF CALCULATION

GENERAL NOTESAND

METHODS OF CALCULATION

RUGOSITÀ

Summary

GENERAL NOTES

RUGOSITÀCONSTRUCTION

OF RADIANT PANEL SYSTEMS

RUGOSITÀCONTROL SYSTEMS

RUGOSITÀFLOW OF HEATFROM A PANEL

RUGOSITÀPANEL DIMENSIONING

3

HISTORIC BACKGROUND

COOLING OF ROOMS

COST OF CONSTRUCTIONAND MANAGEMENT

APPLICATIONS

ADVANTAGES OF PANEL SYSTEMS

HEALTH CONDITIONS

ENVIRONMENTAL IMPACT

HEAT AVAILABLE AT LOW TEMPERATURE

ENERGY SAVING

LIMITATIONS AND DISADVANTAGESOF PANEL SYSTEMS

AIR QUALITY

THERMAL COMFORT

LIMITATIONS CONNECTED WITH SURFACE TEMPERATURE OF FLOOR

THERMAL INERTIA AND METHOD OF USE OF SYSTEM

DISADVANTAGES LINKED WITH DESIGN ASPECTS

G E N E R A L N O T E S

4

HISTORICAL BACKGROUND

It may be of use to analyse the history of panel heating to give a better overallview of its development in the context of systems in general, and, in particu-lar, this may serve to illustrate why these systems are sometimes seen with acertain diffidence, and used only for applications which are entirely secondaryand partial.

THE FIRST FLOOR-HEATING SYSTEMS

The idea of using the floor as a heat emission surface goes back over two thousandyears. Heating systems inspired by this idea were built by the Chinese, Egyptiansand Romans.The system adopted by the Chinese and the Egyptians was fairly simple. It consistedof building an underground hearth and sending smoke under the flooring of therooms to be heated; it was, in practice, single room heating.The Romans, however, used far more complex, advanced systems. Using the smokefrom a single external hearth, they were able to heat several rooms and even severalbuildings, thus achieving the first central-heating type system.

However, it was not until the start of this century that underfloor heating appearedin its present form. And it was an Englishman, Professor Baker, who was first topatent this type of system using the title “systems for heating rooms with hot water car-ried by underfloor piping”. In London in 1909, Crittal Co. acquired the patent rightsand heated one of the Royal palaces with this new system.

However, it was not until the period of the great reconstruction after the secondworld war that a significant spread of panel heating took place.

POST-WAR SYSTEMS

In the early years after World War II, there were two main reasons for the spread ofpanel heating - these were the constant unavailability of heat emitters and the easeof insertion of the panels in prefabricated floor slabs.The technique used consisted of burying 1/2” or 3/4” steel tubes in the flooring,without overlying insulating materials.In Europe, from 1945 to 1950, over 100,000 homes were heated by this tech-nique.

Very soon, however, it was noted that the equipment was causing numerousphysiological problems, such as poor circulation, high blood pressure, headachesand excessive sweating. Problems of this nature were so serious and well-documentedthat certain European countries set up Commissions to identify the causes.

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CAUSES OF PHYSIOLOGICAL PROBLEMS

The results of the various Commissions of enquiry agreed that, in the systemsconstructed, the physiological problems were due to two values being toohigh: (1) the surface temperature of the flooring, and (2) the thermal inertia ofthe floor slabs.

It was demonstrated in particular that, in order to avoid feelings of discomfort, thefloor temperature should not exceed 28÷29°C. In fact, in the systems examined,far higher temperatures were found, even in excess of 40°C. It was also demonstrated that the excessive heat accumulated in the floor slabs of thesystems meant overheating of the rooms above physiologically acceptable levels.

The Commissions themselves, however, did not publish any negative judge-ments of panel systems. They demonstrated that these systems, if constructed for alow surface temperature and with a not excessively high thermal inertia, can offerheat comfort greatly superior than that which can be obtained with radiator or con-vector equipment.

Whilst not being a condemnation, the Commissions results in fact constituteda strong dis-incentive to produce panel systems, and it was some years beforethey made any significant comeback.

THE NEW SYSTEMS

The event which again drew attention to these systems was the energy crisisin the 1970s.Under the impetus of this crisis, almost all European countries issued laws which re-quired efficient heat insulation of buildings, and it was thus possible to heat roomswith less heat and so (in the case of panels) with lower floor temperatures.In addition, in most cases, the degree of insulation required made it possible to heatthe rooms with floor temperatures lower than the physiological maximum, and thisin turn made it possible to reduce the thermal inertia of the system. A further reduction in thermal inertia was obtained by producing “floating” floorswith heat insulation either under the panels or towards the walls.

And it was precisely this innovation, of a legislative and technical nature,which finally made it possible to produce thoroughly reliable panel systemswith a high heat output.

Nowadays in Europe, the “new” panel systems are installed mainly in theNorthern countries, where they are experiencing a deserved success, largelydue to the advantages (analysed below) which they can offer.

6

ADVANTAGES OF PANEL SYSTEMS

The main advantages offered by panel systems relate to:- heat comfort,- air quality,- hygiene conditions,- environmental impact,- the heat usable at a low temperature,- energy saving.

HEAT COMFORT

As shown by the ideal curve shown opposite, in order to ensure comfortable heatconditions in a room, slightly warmer areas must be maintained at floor leveland slightly cooler ones at the ceiling level.The system most suited to providing these conditions consists of radiatingfloors, for the following reasons:

1. the specific position (i.e. on the floor) of the panels;

2. the fact that they give off heat above all by radiation, thus avoiding the for-mation of convection currents of hot air at ceiling level and cold air at floor level.

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AIR QUALITY

Panel heating can prevent two inconveniences which are typical of systemswith heat emitters:

1. burning of the dust in the air, which can cause a feeling of thirst and irrita-tion of the throat;

2. high dust circulation which (especially in rooms which are not regularlycleaned) can cause allergies and respiratory problems.

HEALTH CONDITIONS

Panel systems have a positive contribution to maintaining good environmen-tal health conditions as they prevent:

1. the formation of damp floor areas, thus removing the ideal conditions fordust mites and bacteria;

2. the occurrence of moulds (and the related bacterial fungi) on the walls bor-dering the heated floors.

ENVIRONMENTAL IMPACT

In new buildings and refurbishment works with renewed flooring, panel sys-tems have the least environmental impact because:

1. they do not impose any aesthetic requirements. The invisible nature of thepanels is of great importance, especially when air-conditioning buildings of his-toric or architectural importance, where the presence of heater emitters can com-promise the balance of the original spaces;

2. they do not restrict freedom of layout, thus allowing the most rational use ofthe available space;

3. they do not contribute to deterioration of plasterwork, wooden flooringand hardware, as:

• they do not dirty the walls with convection stains;

• they do not allow formation of damp at floor level;

• they considerably restrict cases of internal condensation, as they increasethe temperature of the walls near the panel floor slabs.

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HEAT USABLE AT LOW TEMPERATURE

Due to their high dispersion area, panel systems can use the heat-carrying fluid atlow temperatures.This characteristic makes their use convenient with heat sources whose effi-ciency (thermodynamic or economic) increases when the temperature requiredis reduced, as in the case of:

• heat pumps,

• condensing boilers,

• solar panels,

• heat recovery systems,

• district heating systems, with heat cost linked (directly or indirectly) to the re-turn temperature of the primary fluid.

ENERGY SAVING

In comparison with the traditional heating systems, panel systems produceconsiderable energy savings, for two basic reasons:

1. the higher operating temperature, which permits (for the same ambient tem-perature) average savings varying from 5 to 10%;

2. the lower temperature gradient between floor and ceiling, which provideshigher energy savings the larger and higher the rooms.

The following are also (although admittedly less important) reasons for energy savings:

• the use of low temperatures which reduces dispersion along the piping,

• the non-heating of the walls behind the radiators,

• the lack of convection movement of the hot air over glazed surfaces.

On average, panel systems, in comparison with traditional systems, produce en-ergy savings of between 10 and 15%.

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LIMITATIONS AND DISADVANTAGES OF PANEL SYSTEMS

These relate mainly to aspects connected (1) with the surface temperature of thefloor, (2) the thermal inertia of the system and (3) difficulties of a design nature.

LIMITATIONS CONNECTED WITH THE SURFACE TEMPERATURE OF THE FLOOR

In order to avoid conditions of physiological discomfort, the surface tempera-ture of the floor must be below the values given under the heading DIMEN-SIONING OF PANELS, sub-chapter SURFACE TEMPERATURE OF THE FLOOR.As specified in the said sub-chapter, these values make it possible to determine themaximum heat output (Qmax) which can be transferred by a panel.

If Qmax is less than the required output (Q), there are two possible situations:

1. Qmax is less than Q only in a few rooms,in which case additional heat emitters can be used. For example, Qmax can comefrom the panels and the remaining output from radiators.

2. Qmax is less than Q in all or most of the rooms,a traditional type system should be used.

THERMAL INERTIA AND METHOD OF USE OF SYSTEM

Panel systems are characterised by having a high thermal inertia as, in orderto transfer heat, they use the structures in which the panels themselves areburied.

In environments heated with a certain degree of continuity (and good insula-tion under the panels), the thermal inertia of the system poses no problems andpermits:

• good adaptability of the system to the external climatic conditions;

• interruptions or slowing down of functions, with system ‘on’ and ‘off’ timeswhich are normally two hours advanced.

On the other hand, in environments which are only heated for brief periods(such as weekend homes), the thermal inertia of the panel system has consider-able phase variations between the starting times and the times of actual use.Thus in these cases, other heating systems should be used.

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DISADVANTAGES LINKED WITH DESIGN ASPECTS

Unlike the traditional systems with heat emitters, panel systems require:

• greater commitment to determining project parameters. In fact, apart fromthe parameters required to determine the heat losses from the rooms, the design ofpanel systems also requires detailed knowledge of all the constructional in-formation regarding the floors and floor slabs.

• more complex, laborious calculations, although due to the greater commit-ment, these can be considerably reduced with the use of computers.

• less adaptation to variants during the work or when the system is completed,as it is not possible to add or remove panel portions, as is done with radiators.

COOLING ROOMS

Panel systems also permit cooling of premises. It should however be consid-ered that these have two very clear limitations:

1. the limited cooling output,

2. the inability to dehumidify.

The low cooling output depends on the fact that in panel systems it is notpossible to reduce the floor temperature too far without causing surface con-densation phenomena. For this reason, it is difficult to obtain a cooling outputgreater than 40-50 W/m2.

The inability to dehumidify depends in fact on the nature of the panel systemitself, whose surfaces (i.e. the floor) cannot cause condensation and evacuationof part of the water contained in the air. Healthy hygrometric conditions can,therefore, only be obtained with the use of dehumidifiers, in conjunction with panelsystems, with a cost and space requirement which is not always acceptable.

12

CONSTRUCTION AND DESIGN COSTS

It is practically impossible to establish significant mean data with regard tothe costs of installing panel systems, as there are too many variables involved,such as:– the type of system (stand-alone or centralised),– the control system, – the heat resistance of the floors,– the costs of other insulating materials to be laid below the panels,– the cost and quality of the pipe forming the panels.

It can however be assumed that panel systems will cost on average 10% to30% more than radiator systems with climatic control.

With regard, however, to running costs, panel systems allow savings averag-ing 10 to 15% in comparison with traditional systems (see sub-chapter ENERGYSAVING). They thus allow the additional construction cost to be offset relativelyquickly.

APPLICATIONS

On their own, or integrated with air-conditioning systems, panel systems canbe used to heat: detached and terraced houses, homes in high-rise blocks, nursinghomes, schools, gyms, swimming pools, museums, libraries, hospitals, hotels, shopsand workshops.

They can also be used to clear ice and snow - car parks, garage ramps, steps, run-ways and sports fields.

13

PRESSURE TEST AND START-UP

PANEL CONTAINMENTSTRUCTURES

MAIN JOINTS

EDGE JOINTS

SLABS

FLOORS

DISTRIBUTION OF HEAT-CARRYING FLUID

PERIPHERAL JOINTS

INSULATING MATERIALS

MANIFOLDS

PANELS

C O N S T R U C T I O NO F R A D I A N T P A N E L S Y S T E M S

14

PANEL CONTAINMENT STRUCTURES

These consist mainly of the floor (or solid foundation on the ground), the insulat-ing material, the slab and the floor tiles or finish.

15

INSULATING MATERIALS

The insulation under the panels is used (1) to reduce the heat given off down-wards and (2) to limit the thermal inertia of the system.

The most commonly used insulating materials are polystyrene and polyurethane.Sometimes, lightened concretes are also used, but their use is generally not recom-mended, because they have high thermal inertia values.

Insulation systems can have flat surfaces or pre-formed surfaces for direct an-chorage of the pipes.

Flat surface insulation materials are normally used in buildings to insulate tradi-tional floors.As they have no supports for anchoring pipes, they require the use of electro-weldedframeworks or suitable metal profiles with junction clips and fixing supports.The most frequently used flat surface insulating materials are expanded and extrudedpolystyrene. The latter, in particular, due to form and high density, make itpossible to produce very compression-resistant floors.

Pre-formed insulation, on the other hand, is made specifically for the panel system.Its surfaces have profiles and grooves which allow the pipes to be fitted directly.These insulators have the advantage of speeding up the fitting of the panels.They are, however, not highly compression-resistant and thus cannot be used tomake floors subject to compression stresses, such as for example industrial flooring.

If several materials are to be used for making the insulating layer, the leastcompression-resistant materials must be positioned in the upper layers. In ad-dition, the insulating panels must be fitted in close contact with each other and (inthe case of multiple layers) have offset joints.

In order to prevent deterioration of the insulating materials in use, two typesof protection must be provided for:

1. Protection against the dampness of the concrete.This is always required and can be made above the insulation with polyethylenesheets (min. thickness 0,15 mm) or other equivalent protection;

2. Protection against rising damp.This is only required for floors in direct contact with the ground or in verydamp rooms. It can be made under the insulation with polyvinyl chloride sheets(min. thickness 0,4 mm) or other equivalent protection

16

PERIPHERAL JOINTS

These are used to provide (1) expansion of the floor slab, (2) heat insulationbetween the slab and the walls, (3) a sound gap between floor and walls.

This is done using insulating strips (normally expanded polyethylene 6÷8 mmthick) positioned along the walls and bounding the various construction ele-ments of the floor and slab (see diagram in the chapter PANEL CONTAINMENTSTRUCTURES).

The strips must be positioned carefully and overlapped by at least 10 cm at the junc-tion points. Their upper parts must protrude beyond the block and be trimmed onlywhen the floor is finished.

MAIN JOINTS

These permit expansion of the slab at the locations of the structural joints ofthe building and in the case of large floor areas.

Without joints of this type, constructing floors of area exceeding 40 m2 or of lengthgreater than 8 m is not advisable. In L-shaped rooms, the maximum area can be ex-tended to 80 m2.

17

EDGE JOINTS

These are used to guide the positioning of the slab in relation to doors andother openings.They are made using a trowel (up to a depth of 3÷4 cm) when the slab begins to dry.

SLAB

This must be made with a fluid mixture to prevent the formation of small airpockets which can obstruct normal heat transfer. Appropriate chemicals can beadded to improve the fluidity of the casting.

The components and proportions of the mix depend on the class of strengthto be obtained.

The minimum thickness of the slab over the pipes must be:

• 20 mm for flush slabs, i.e. for slabs on which a sub-base is to be made later,onto which the tiles will be fitted.

• 40 mm for finish slabs, i.e. for slabs on which the floor is to be laid or “stuck”directly afterwards.

TILES (FLOOR FINISH)

Panel systems do not require special types of flooring or special techniques for fit-ting.However, it is advisable not to use floor finishes with a thermal resistancegreater than 0,150 m2K/W (see item PANEL DIMENSIONING, sub-chapter FLOORTHERMAL RESISTANCE).

18

DISTRIBUTION OF THE HEAT-CARRYING FLUID

This consists of taking the fluid through the main distribution system, the manifoldsand the panels. For the development and dimensioning of the main system, see the 2nd

Caleffi Handbook; the main characteristics of the manifolds and the panels are exa-mi-ned below.

MANIFOLDS

These are normally made of brass with independent flow and return connec-tions. For correct operation and maintenance of the system, they must have:– main on/off valves,– panel on/off valves,– micrometric panel regulating valves,– automatic air vents,– drain cocks.

19

PANELS

The analysis of their main characteristics is broken down into three parts:– the choice of pipes,– the formation of the panels,– the installation of the pipes.

Selection of pipes

Plastic pipes are the most suitable for forming the panels, being differentfrom metal pipes in that they:• are easy to install,• are not subject to corrosion,• do not allow the formation of scale.

Normally, cross-linked polyethylene (PEX), polybutene (PB) and polypropy-lene (PP) pipes are used.All the plastic pipes must have barriers to prevent the diffusion of oxygen. Theoxygen contained in the air must be prevented from diffusing into the pipes, as thisgas can cause corrosion of the boiler and any metal pipework.

The diameters usually used for making the panels are 16/13 and 20/16. 12/10 and25/20 are used only for special applications.

Formation of the panels

Each room must be heated with one or more specific panels. This makes it pos-sible to control room temperatures independently, in other words without alteringthe heat balance of other rooms.

The panels can be made spiral or coiled. These are systems which, with the samedistance between centres and surface, deliver the same amount of heat, but the spiralsystem is generally preferable as:

• it provides a more even surface temperature as (unlike the case of the coil), itsflow and return pipes lay alternately;

• it is easier to implement, as the shape of the spirals only requires two bends at180° to the central ones, in other words those in which the formation of the spiralis inverted.

The coil formation is suited above all to rooms of irregular shape or specialapplications, such as, for example, de-icing ramps.

20

The panels can have constant or variable centre-to-centre distances with pipescloser together where there are areas of glass or highly dispersive walls.

21

With coil panels, the flow must be towards the outer walls in order not to in-crease the already sensitive differences in surface temperature at the floor, whichcharacterise this distribution system.

The distances between pipes and the structures bounding the environmentmust be at least:• 5 cm in the case of walls and pillars,• 20 cm in the case of flue ducts, fireplaces and lift shafts.

The pipes of the panels must not interfere with discharge pipes and must notpass under sinks, shower trays, WCs or bidets, unless these are of the suspended type.

22

Installation

The pipes must be transported, stored and fitted in such a way as to avoid sitedamage and direct exposure to sunlight.

Various systems can be used when installing the pipes, such as:• pre-formed insulation of appropriate profiles and grooves,• electro-welded frameworks with fixing clips or clamps,• metal profiles with fitting and jointing clips.

In all cases, only fitting systems must be used which are able to:– permit good pipe anchorage,– prevent damage to the pipes themselves (metal connections are not permitted),– permit the design centre-to-centre distances to be implemented.

It is advisable not to pass pipes through the main expansion joints.If this is not possible, the work must be done in such a way that:

1. the expansion joints of the building are only crossed by the pipes of the maindistribution system;

2. the other main joints are crossed only by pipes protected with a sheath of com-pressible material of• min. length 30 cm on either side of the joint,• diameter double the external diameter of the pipe.

23

PRESSURE TEST AND START-UP

Before covering with concrete, the panels must be tested at a pressure at leastequal to the working pressure, with a minimum of 6 atm. This pressure mustbe maintained and constantly checked throughout the spreading of the concrete.If there is a risk of frost, antifreeze additives compatible with the panel pipesshould be used.

The system must not be activated until the slab and the floor are completelydry. In general, this takes at least 21 days from casting. The use of synthetic addi-tives makes it possible to reduce this period considerably, but it will still be not lessthan 7 days.

The heating must be started maintaining a flow temperature of 25°C for atleast 3 days. Subsequently, the flow temperature can be gradually raised to the de-sign value.

24

Climatic controlwith pre-assembled unit

Climatic controlwith 3-way valve


upstream from a heat exchanger

Fixed point regulationwith 3-way valve

and anti-condensation pump


and anti-condensation pump

Climatic controlwith 3-way valve,

anti-condensation pump and by-pass

C O N T R O L S Y S T E M S

25

Panel system control equipment must be able to:

1. permit the heat transfer required to take place in such a way as to optimisethe heat comfort and energy saving;

2. prevent excessively hot fluid from being distributed to the panels, as thiscould cause breakage and cracking of the flooring and wall structures;

3. prevent flue condensation in the boiler, so as not to cause corrosion problemswhich could endanger the boiler itself.

In order to optimise the heat emission, climatic type controls should usuallybe adopted. In fact these controls make it possible to minimise the heat accumulat-ed in the floor slabs and thus in turn to minimise the time required for the system torespond to variation of the required heat output. Either simple climatic controls orintegrated climatic controls with thermoelectric valves interlocked with room ther-mostats can be conveniently adopted.Fixed point controls are suggested only for systems which are not workingcontinuously, used for example to heat churches, theatres or exhibition rooms.

However, in order to prevent the flow of excessively hot fluid to the panels,the system must be provided with a safety sensor able, when the preset limit isexceeded, to close the control valve and shut down the system pump.This sensor should be protected against tampering.

Finally, in order to prevent flue condensation, the boiler return temperaturemust be maintained at over 55°C.For this purpose, anti-condensation pumps and motorised valves with override de-vices can be used.

Operating diagrams of the systems most used for controlling panel systemsfollow.

26

Climatic control with pre-assembled unit

This solution is valid for small to medium-sized systems. Generally, the pre-as-sembled units available do not permit flows greater than 5.000÷6.000 l/h.

27

Climatic control with 3-way valve

This control can be adopted in systems where there are not problems withflue gas condensation; for example in systems with heat pumps or heat exchangers.

28

Climatic control with 2-way valves upstream from a heat exchanger

This type of control can be used in district heating substations.

29

Fixed point regulation with 3-way valve and anti-condensation pump

This solution is suited to systems operating intermittently, as it minimises thetime required to reach the steady condition. It does not, however, allow a goodresponse to output variations in continuous operation.

30

Climatic control with 3-way valve and anti-condensation pump

This system is mainly suited to panel systems of medium and large dimensions.

Advantages: It is easy to operate and check, as it is similar to the control sys-tems used in heating plant.

Disadvantages: The 3-way valve operates in a limited opening range.In order to prevent chatter and wear on the valve (seat and obturator),high-quality materials and equipment must be used.

31

Climatic control with 3-way valve, anti-condensation pump and by-pass

This system is mainly suited to panel systems of medium and large dimensions.

Advantages: The 3-way valve operates throughout its whole openingrange, thus preventing any chatter and wear on the valve.

Disadvantages: Requires skilled personnel for commissioning and calibration.

32

The diagram on the previous page shows the regulating and by-pass valves di-mensioned on the basis of the following flows:

QtotGv = —————————

1,16 . ( tm – t r )

Gb = Gp – Gv

where:

Gv = flow through 3-way valve, l/hQtot = total heat output of panel circuit, W

tm = primary circuit flow temperature (boiler circuit), °Ct r = secondary circuit return temperature (panels circuit), °C

Gb = by-pass flow, l/hGp = panels circuit flow, l/h

(1)

(2)

33

CALCULATION PARAMETERS

UPWARD FLOW OF HEATFROM A PANEL

FACTOR RELATING TO FLOOR THERMAL RESISTANCE

FACTOR RELATING TO PIPE CENTRE-TO-CENTRE DISTANCE

FACTOR RELATING TO THICKNESS OF SLAB ABOVE PIPES

FACTOR RELATING TO OUTER DIAMETER OF PIPE

TOTAL FLOW OF HEAT FROM A PANEL

FACTOR RELATING TO PIPE CHARACTERISTICS

LOGARITHMIC MEAN BETWEEN FLUID TEMPERATURE

AND ROOM TEMPERATURE

F L O W O F H E A TF R O M A P A N E L

In order to be able to use the programme, you do not need to read the chap-ters and sub-chapters marked with an asterisk (see preface).

*

*

*

*

*

*

*

*

34

CALCULATION PARAMETERS

The parameters which are used to determine the heat output delivered by a panel canbe broken down into the following groups:

1. parameters relating to the surrounding conditions:- t a room temperature, °C

- t s temperature of room or ground below, °C

2. parameters relating to the panel configurations:- S covered surface of panel, m2

- I pipe fitting centre-to-centre distance, m

3. parameters relating to the type of pipe:- De pipe external diameter, m- Di pipe internal diameter, m - λλ t pipe thermal conductivity, W/mK

4. parameters relating to the panel containing structure:- Rp thermal resistance of floor, m2K/W

- sm thickness of slab above pipes, m- λλ m thermal conductivity of the slab, W/mK

- Rs thermal resistance under panel, m2K/W

5. parameters regarding the temperature of the heat-carrying fluid:- t e flow temperature of heat-carrying fluid, °C

35

36

UPWARD FLOW OF HEAT FROM A PANEL (1)

This is calculated using the following formula:

Q = S . ∆∆t . B . Fp . F I . Fm . F D

where: Q = upward flow of heat given off by panel, WS = covered surface of panel, m2

∆∆t = logarithmic mean between the temperature of the fluid and the ambienttemperature, °C

B = factor relating to pipe characteristics, W/m2K

Fp = factor relating to thermal resistance of floor, dimensionlessF I = factor relating to centre-to-centre distance of pipes, dimensionlessFm = factor relating to thickness of slab above pipes, dimensionlessF D = factor relating to outer diameter of pipe, dimensionless

(1) There is no need to read this chapter (see Preface).

(1)

37

LOGARITHMIC MEAN BETWEEN THE TEMPERATURE OF THE FLUID ANDTHE AMBIENT TEMPERATURE (1)


( t e – tu )∆∆t = ———————( t e – t a )ln —————( tu – t a )

where: ∆∆t = logarithmic mean of fluid temperature and ambient temperature, °C

te = flow temperature of heating fluid, °Ctu = return temperature of heating fluid, °C

ta = temperature of ambient air, °C

ln = natural logarithm

(1) There is no need to read this sub-chapter (see Preface).

(2)

38

FACTOR RELATING TO THE PIPE CHARACTERISTICS (1)

This is indicated by the symbol B and it is considered that:

B = B 0 = 6,7 W/m2K for pipes with: - s t0 = 0,002 thickness, m- λλ t0 = 0,350 thermal conductivity, W/mK

For pipes of different thickness and thermal conductivity, the factor (B) is calculatedusing the formula (3) shown below:

1 1 1,1 1 De 1 De— = —— + —— . Fp . F I . Fm . F D . I . (—— ln —— – —— ln —— )B B 0 π 2λλ t De – 2st 2λλ t0 De – 2st0

where: B 0, s t0, λλ t0 = symbols and values defined above

Fp = factor relating to the thermal resistance of the floor, dimensionlessF I = factor relating to the centre to centre distance of the pipes, dimensionlessFm = factor relating to the thickness of the slab above the pipes, dimensionlessF D = factor relating to the outer diameter of the pipe, dimensionless

I = pipe centre-to-centre distance, mDe = outer diameter of pipe, mλλ t = thermal conductivity of pipe, W/mKs t = thickness of pipe, m

ln = natural logarithm


39

FACTOR RELATING TO THE THERMAL RESISTANCE OF THE FLOOR (1)

This is shown with the symbol Fp. Its value can be determined from Table 1,or using formula (4).

TABLE 1 - Value of factor Fp

Conductivity Thermal resistance of floor, m2K/Wof slab

W/mK 0,00 0,05 0,10 0,15

2,0 1,196 0,833 0,640 0,519

1,5 1,122 0,797 0,618 0,505

1,2 1,058 0,764 0,598 0,491

1,0 1,000 0,734 0,579 0,478

0,8 0,924 0,692 0,553 0,460

0,6 0,821 0,632 0,514 0,433

1 sm0——— + ———

αα λλ m0Fp = —————————

1 sm0——— + ——— + Rp

αα λλ m

given: αα = 10,8 W/m2Ksm0 = 0,045 mλλ m0 = 1,0 W/mK

and where: λλ m = thermal conductivity of slab, W/mKRp = thermal resistance of floor, m2K/W


(4)

40

FACTOR RELATING TO PIPE CENTRE-TO-CENTRE DISTANCE (1)

Shown by the symbol F I and calculated using the formula:

F I = A Ix

where the factor A I can be determined from Table 2 and the exponent x (forpipe centre-to-centre distances varying between 0,050 and 0,375 m) can be calculat-ed using the equation:

Ix = 1 – —————

0,075

where: I = pipe centre-to-centre distance, m

TABLE 2 - Value of factor A I

Rp = 0,00 Rp = 0,05 Rp = 0,10 Rp = 0,15

A I = 1,230 A I = 1,188 A I = 1,156 A I = 1,134

Table symbols:

Rp = thermal resistance of floor, m2K/WA I = dimensionless factor

N.B.:

For centre-to-centre distances greater than 0,375 m, the heat flow (Q) can becalculated using the formula:

0,375Q = Q (0,375) . ————

I

where Q (0,375) represents the heat flow from a panel with centre-to-centre distancesequal to 0,375 m.


(5)

(6)

(7)

41

FACTOR RELATING TO THE THICKNESS OF THE SLAB ABOVE THE PIPES (1)

Shown by the symbol Fm and calculated using the formula:

Fm = Amy

where the factor Am can be determined from Table 3 and the exponent y (for thicknessof the slab above the pipes greater than 0,015 m) can be calculated using the equation:

y = 100 . ( 0,045 – sm )

where: sm = thickness of the slab over the pipes, m

TABLE 3 - Value of factor Am

Centre-to- Thermal resistance of the floor, m2K/Wcentre

distance0,00 0,05 0,10 0,15

0,050 1,0690 1,056 1,0430 1,0370

0,075 1,0660 1,053 1,0410 1,0350

0,100 1,0630 1,050 1,0390 1,0335

0,150 1,0570 1,046 1,0350 1,0305

0,200 1,0510 1,041 1,0315 1,0275

0,225 1,0480 1,038 1,0295 1,0260

0,300 1,0395 1,031 1,0240 1,0210

0,375 1,0300 1,024 1,0180 1,0160


(8)

(9)

42

FACTOR RELATING TO THE PIPE OUTER DIAMETER (1)

Indicated by the symbol F D and calculated using the formula:

F D = A D z

where the factor A D can be determined from Table 4 and the exponent z (fordiameters between 0,010 and 0,030 m) can be calculated using the equation:

z = 250 . ( De – 0,020 )

where: De = outer diameter of pipe, m

TABLE 4 - Value of factor A D

Centre-to- Thermal resistance of the floor, m2K/Wcentre

distance0,00 0,05 0,10 0,15

0,050 1,013 1,013 1,012 1,011

0,075 1,021 1,019 1,016 1,014

0,100 1,029 1,025 1,022 1,018

0,150 1,040 1,034 1,029 1,024

0,200 1,046 1,040 1,035 1,030

0,225 1,049 1,043 1,038 1,033

0,300 1,053 1,049 1,044 1,039

0,375 1,056 1,051 1,046 1,042


(10)

(11)

43

TOTAL FLOW OF HEAT FROM A PANEL (1)

This is determined using the equation:

Qt = ( te – tu ) . G . 1,16

where: Qt = total heat output emitted by a panel, W

te = heating fluid flow temperature, °Ctu = heating fluid return temperature, °C

G = flow through panel, l/h

The flow through the panel can be calculated using the formula (13) given below:

1 sm——— + Rp + ———

Q αα λλ m S . ( ta – t s )G = —————— . [ 1 + —————— + ————— ]( te – tu ) . 1,16 Rs Q . Rs

given: αα = 10,8 W/m2K

and where: G = flow through panel, l/hQ = upward flow of heat from a panel, W

te = heating fluid flow temperature, °Ctu = heating fluid return temperature, °C

sm = thickness of slab, mλλ m = thermal conductivity of slab, W/mK

Rp = thermal resistance of floor, m2K/WRs = thermal resistance under panel, m2K/W

S = covered surface of panel, m2

ta = temperature of ambient air, °Ct s = temperature of room or ground below °C


(12)

44

CALCULATION OF PANELS

PARAMETERS REQUIRED

MAX. DESIGN TEMPERATURE

AMBIENT TEMPERATURE

TEMPERATURE OF ROOM OR GROUND BELOW

THERMAL RESISTANCE OF FLOOR

THERMAL RESISTANCE UNDER PANEL

HEAT OUTPUT REQUIRED

PRESET HEAD

CENTRE-TO-CENTRE DISTANCES

D I M E N S I O N I N G O F P A N E L S

PARAMETERS TO BE DETERMINED

PANEL FLOW

PANEL LENGTH

FLUID VELOCITY

TOTAL HEAT OUTPUT FROM PANEL

HEAT OUTPUT EMITTED DOWNWARDS

REQUIRED HEAD

TEMPERATURE DIFFERENCE OF HEATING FLUID

SURFACE TEMPERATURE OF FLOOR

MEAN HEAT OUTPUT EMITTED UPWARDS BY ONE METRE OF PIPE

MEAN HEAT OUTPUT EMITTEDDOWNWARDS BY ONE METRE OF PIPE

45

CALCULATION OF PANELS (1)

The formulae examined in the previous items make it possible to dimensionpanel systems. For this purpose, a method of theoretical calculation is presentedbelow, with pre-established head at the ends of the panel. The analysis and de-velopment of the proposed method is broken down into the following stages:

A. checking the conditions for physiological well-being,

B. calculation of the return temperature,

C. calculation of the flow,

D. calculation of the panel length,

E. calculation of the head losses of the panel,

F. check on acceptability of required head,

G. calculation and checking of other parameters,

H. zone head.


46

A - Checking the conditions for physiological well-being

In order to be able to ensure conditions of physiological well-being, the heat out-put transferred by the panel must not exceed the maximum output defined insub-chapter SURFACE TEMPERATURE OF THE FLOOR. It must therefore be:

Q < Qmax = S . qmax

where:Q = heat output required from the panel, WQmax = maximum output which can be transferred by the panel, WS = covered surface of panel, m2

qmax = specific output which can be transferred by the panel, W/m2

where:qmax = 100 W/m2 in continuously occupied environments;qmax = 150 W/m2 in bathrooms, showers and swimming pools;qmax = 175 W/m2 in perimeter areas of rooms rarely used.

If Q is greater than Qmax, a heat output less than or equal to Qmax must beemitted by the panel and the remaining output made up by an integratedheat emitter.

B - Determination of the return temperature

Noting the parameters:

- heat output required,- panel surface,- maximum design temperature,- ambient temperature,- thickness and conductivity of slab,- thermal resistance of floor,- outer diameter, thickness and conductivity of pipe,- pipe centre-to-centre distance,

the return temperature (tu) of the panel is calculated for successive itera-tions, using the formulae (1) and (2) given under the heading HEAT FLOWFROM A PANEL.

(1)

47

There are three possible situations:

B1. The return temperature is not lower than the flow temperature.In this case, the panel is not capable of emitting the required heat, and istherefore under-dimensioned.

As an alternative solution, one can:• select (if possible) a panel with smaller centre-to-centre distances -

i.e. a panel with a greater heat output;• provide for an integrated heat emitter.

B2. The return temperature is not higher than the ambient temperature.In this case, the panel only operates intermittently in the heat transfer tothe environment, and is thus over-dimensioned.

As an alternative solution, one can:• select (if possible) a panel with larger centre-to-centre distances - i.e.

a panel with a lower heat output;• provide for a panel with a smaller emission surface.

B3. The return temperature is between the flow and ambient tem-peratures.In this case, the value of the return temperature does not (at least from thetheoretical point of view) restrict the acceptability of the solution underconsideration.

However, the difference between the maximum flow temperatureand the return temperature is below the limits given in the sub-chap-ter TEMPERATURE DIFFERENCE OF HEATING FLUID.

C - Calculation of flow

Noting the parameters defined in B, the return temperature (tu), the thermal re-sistance under the panel and the temperature of the room or ground below, thepanel flow can be calculated using the formula (13) given in the previousitem.

48

D - Calculation of panel length

The panel length is calculated using the equation:

SL = La + ——

I

where:L = panel length, mLa = route length (both ways) between manifold and panel, mS = covered surface of panel, m2

I = panel centre-to-centre distance, m

E - Calculation of the head losses of the panel

The total head losses of the panel are calculated by adding together the contin-uous and localised losses of head, the value of which is determined as follows:

- the continuous head losses are calculated by multiplying the length of thepanel by the unit head losses;

- the localised head losses are calculated by adding together head losses due to:

• the panel shut-off valves,

• the panel pipe bends (on average these losses are considered to be between20 and 30% of the continuous head losses).

F - Check on acceptability of required head

On the basis of the value of the head required at the ends of the panel (whichcoincides with the head losses determined above), there are two possible cases:

F1. The head required is lower than that pre-established.In this case, the panel is acceptable and the difference between the head re-quired and that pre-established is offset by adjustment of the regulatingvalve provided for each panel.

(2)

49

F2. The head required is higher than that pre-established.In this second case, the solution prepared is not acceptable.As an alternative solution, one can:

• select (if possible) a panel with smaller centre-to-centre distances;

• consider the possibility of transferring to the room a slightly lowerheat output, as a few watts less may take the required head below thatpre-established;

• provide for an additional heat emitter.

G - Calculation and checking of other parameters

In addition to the limits connected with the temperature of the floor andthe pre-established head , solutions whose velocity is too low must also beavoided (see sub-chapter FLUID VELOCITY)

In addition, in order to be able to proceed with the dimensioning of theheat generator and other panels, the following parameters must also bedetermined (see sub-chapter PARAMETERS TO BE DETERMINED):

Qt = total heat output emitted by panel,

Qs = heat output emitted downwards by panel,

ep = mean heat output emitted upwards by one metre of pipe,

es = mean heat output emitted downwards by one metre of pipe.

H - Zone Head

This is calculated by adding together the following:

Hp = pre-established head at the panel connections,

Hc = loss of head due to the manifold,

Hz = loss of head due to the possible presence of the zone valve,

Hi = loss of head due to main shut-off valves.

50

PARAMETERS REQUIRED

In order to be able to dimension a panel, the following parameters must be known:

centre-to-centre distances (in the case of panels with variable centre-to-centre distances); outer diameter, thickness and thermal conductivity of pipe; pre-established head; maximum design temperature; heat output required; manifold-panel travel distance; ambient temperature; temperature of room or ground below; covered surface of panel; thickness and conductivity of slab; thermal resistance of floor finish; thermal resistance under panel; fluid-dynamic characteristics of the manifold and valves.

Those of greatest design interest are examined below:

CENTRE-TO-CENTRE DISTANCES

These may vary up to 30 cm in applications of a domestic nature or in perma-nently inhabited environments. They may, however, vary up to 40 cm in ap-plications of an industrial or commercial nature (e.g.workshops, warehouses orgarages).

The grid (or series) of possible centre-to-centre distances depends on the fixingsupports (framework or profiles) or the pre-formed panels to be used.

The most frequently used grids are as follows:

7,5 15,0 22,5 30,0 37,5

5,0 10,0 15,0 20,0 30,0

8,0 16,0 24,0 32,0 40,0

51

PRESET HEAD

This is the head which is assumed to be available at the ends of the panel.It is generally agreed that this can vary from:

– 1.200 to 1.500 mm w.g. for wall heating units, as they have limited headcirculation pumps;

– 1.500 to 2.500 mm w.g. for floor-standing boilers, heat exchangers orheat pumps.

MAXIMUM DESIGN TEMPERATURE

This is the maximum temperature of the heating fluid circulating in the panels.Here, values should be used varying from:

– 45 a 55°C with traditional boilers;

– 40 a 45°C with district heating, condensing boilers, heat pumps;

– 32 a 38°C with solar panels.

These values make it possible to obtain a good compromise between two dif-ferent requirements:

• restricting the length (and thus the cost) of the panels,

• optimising the efficiency of the heat source.

It is thus considered that low temperature heating is possible only with floorsof limited thermal resistance (see sub-chapter THERMAL RESISTANCE OFFLOOR).

It is advisable that the maximum design temperature should not exceed 55°Cin order to avoid:

• creep in tiled floors;

• cracking in parquet floors;

• subsidence of floorings made or rubber or other synthetic materials;

• “wave” floor temperatures, i.e. with considerable variations of hot zones and coldzones.

52

HEAT OUTPUT REQUIRED

This is the output required from the panel to handle the thermal requirementof the room to be heated. This requirement must be calculated taking intoconsideration two typical aspects of rooms heated with panel systems:

• the lack of heat loss through the floors,

• the heat contribution of any panels located on the floor above.

AMBIENT TEMPERATURE

This is the air temperature to be achieved within the room. Its value is gener-ally imposed by law or by contractual clauses.

Given equal ambient temperatures, it is considered that in a room heated with pan-els, the operating temperature (i.e. the temperature which will give a good ap-proximation to heat comfort in the room) is on average 1÷1,5°C higher than thatwhich can be obtained by heating with heat emitters (see Item GENERALNOTES, sub-clause ENERGY SAVING).

53

TEMPERATURE OF THE ROOM OR GROUND BELOW

This is the temperature of the room or ground below the structure containingthe panels. To determine this, two situations must be considered:

1. room located under the slab containing the panels:its temperature is determined by the same criteria used for calculating heat losses.

2. ground under the slab containing the panels:its temperature can be determined by means of the following table:

TAB. 1 - Average temperature of the ground in relation to the outside temperature

Outside Average temperaturetemperature of ground

under floor

- 20°C + 3°C

- 15°C + 5°C

- 10°C + 8°C

- 5°C + 10°C

0°C + 11°C

+ 5°C + 12°C

54

THERMAL RESISTANCE OF FLOOR

This is calculated using the formula:

sp

Rp = ———λλ p

where: Rp = thermal resistance of the floor, m2K/Wsp = thickness of floor, mλλ p = thermal conductivity of floor, W/mK

Table (2) shows the thermal conductivity of materials used for making floor finishes.

TAB. 2 - Conductivity of materials used for flooring

Material ConductivityW/mK

Ceramic 1,00

Brick 0,90

Rubber 0,28

Granite 3,20

Linoleum 0,18

Marble 3,40

Carpet 0,09

Parquet 0,20

PVC flooring 0,23

The following tables contain pre-calculated values of the thermal resistance Rp

of flooring in ceramic, brick, rubber, marble and parquet.

(3)

55

Table (3) shows the indicative values of the maximum specific heat outputwhich can be transferred by a panel, in relation to two variables; the thermal re-sistance of the floor and the maximum design temperature.These values (averagely valid for temperature differences of 8-12°C and for plasticpipes of outer diameter between 20 and 16 mm) can be used to determine (alwayswith a certain degree of approximation):

1. the heat output of a panel when the floor type is varied;

2. the maximum design temperature in relation to the specific output requestedand the thermal resistance of the floors used.

TAB. 3: Indicative values of the maximum specific heat output [W/m2] which can be transferred by a panel

Rp Maximum Design Temperature, °Cm2K/W

30 32 34 36 38 40 42 44 46 48 50

0,000 48 58 68 79 89 99 109 119 130 140 150

0,010 45 54 64 74 83 93 102 112 121 131 141

0,020 42 51 60 69 78 87 96 105 114 124 133

0,030 40 48 57 66 74 83 91 100 108 117 126

0,040 38 46 54 62 70 79 87 95 103 111 119

0,050 36 44 52 59 67 75 83 90 98 106 114

0,060 34 42 49 57 64 72 79 86 94 101 109

0,070 33 40 47 54 61 68 76 83 90 97 104

0,080 31 38 45 52 59 66 73 79 86 93 100

0,090 30 37 43 50 57 63 70 76 83 90 96

0,100 29 35 42 48 55 61 67 74 80 87 93

0,110 28 34 40 46 53 59 65 71 77 83 90

0,120 27 33 39 45 51 57 63 68 74 80 86

0,130 26 32 37 43 49 55 60 66 72 78 83

0,140 25 31 36 42 47 53 58 64 70 75 81

0,150 24 30 35 40 46 51 57 62 67 73 78

56

CERAMIC

TAB. 4 - Value of Rp for λλ p = 1,00 W/mK

s Rp

6 0,006

8 0,008

10 0,010

12 0,012

BRICK


s Rp

10 0,011

15 0,017

20 0,022

30 0,033

RUBBER


s Rp

2 0,007

3 0,011

4 0,014

5 0,018

57

Table symbols: Rp = thermal resistance of floor, m2K/Ws = thickness of floor, mmλλ p = thermal conductivity of floor, W/mK

MARBLE


s Rp

10 0,003

15 0,004

20 0,006

30 0,009

PARQUET


s Rp

6 0,030

8 0,040

10 0,050

12 0,060

14 0,070

16 0,080

18 0,090

20 0,100

58

THERMAL RESISTANCE UNDER PANEL

This is the thermal resistance of the structure below the top level of the pipesand the surrounding environment

This is calculated using the formula:

sd s is s in 1Rs = —— + —— + Rsl + —— + ——

λλ m λλ is λλ in αα

given: αα = 5,9 W/m2K

and where:Rs = thermal resistance under panel, m2 K/W

sd = distance between upper level of pipes and insulation, mλλ m = thermal conductivity of the slab, W/mK

s is = thickness of insulating material, mλλ is = thermal conductivity of insulating material, W/mK

Rsl = thermal resistance of floor slab, m2K/W

s in = thickness of plaster, mλλ in = thermal conductivity of plaster, W/mK

(4)

59

Table (9) shows the conductivity and thermal resistance of materials commonly locat-ed under the panels.

TAB. 9 - Conductivity or thermal resistance of materials located under panels

Material Conductivity Thermal resistance

W/mK m2K/W

Expanded clay 0,100

Concrete 1,300

Fibreglass 0,040

Plaster with lime and gypsum 0,700

Plaster with lime mortar 0,900

Polystyrene 0,035

Polyurethane 0,028

Brick floor slab: 20 cm 0,32

24 cm 0,35

28 cm 0,37

Boards: 15 cm 0,36

20 cm 0,40

25 cm 0,43

Cork sheets 0,040

Expanded cork with binders 0,045

Expanded vermiculite 0,070

The following pages contain tables with precalculated values of thermal resis-tance Rs for floor slab in brick, boards and floors on the ground.

60

FLOOR SLABS OF BRICK WITHPOLYSTYRENE INSULATION

FLOOR SLABS OF BOARDS WITHPOLYSTYRENE INSULATION

TAB. 10 - Rs as function of h e s

h s Rs

2,0 1,061

2,5 1,204

3,0 1,347

20 3,5 1,490

4,0 1,633

4,5 1,776

5,0 1,919

2,0 1,091

2,5 1,234

3,0 1,377

24 3,5 1,520

4,0 1,663

4,5 1,806

5,0 1,949

2,0 1,111

2,5 1,254

3,0 1,397

28 3,5 1,540

4,0 1,683

4,5 1,826

5,0 1,969


h s Rs

2,0 1,101

2,5 1,244

3,0 1,387

15 3,5 1,530

4,0 1,673

4,5 1,816

5,0 1,959

2,0 1,141

2,5 1,284

3,0 1,427

20 3,5 1,570

4,0 1,713

4,5 1,856

5,0 1,999

2,0 1,171

2,5 1,314

3,0 1,457

25 3,5 1,600

4,0 1,743

4,5 1,886

5,0 2,029

Symbols, tables 10 and 11: Rs = thermal resistance under panel, m2K/Ws = thickness of insulating material, cmh = height of floor slab, cm

61

FLOOR ON THE GROUND WITH POLYSTYRENE INSULATION


h s Rs

2,0 0,687

2,5 0,830

3,0 0,973

8 ÷ 12 3,5 1,115

4,0 1,258

4,5 1,401

5,0 1,544

Symbols, table 12: Rs = thermal resistance under panel, m2K/Ws = thickness of insulating material, cmh = thickness of concrete slab, cm

62

PARAMETERS TO BE DETERMINED

For the correct and complete dimensioning of a panel, it is necessary to deter-mine the following parameters:

surface temperature of floor; temperature difference of heating fluid; flow in panel; head required; lenght of panel; fluid velocity; total heat output emitted by panel; heat output emitted downwards; mean heat output emitted upwards by one metre of pipe; mean heat output emitted downwards by one metre pipe.

SURFACE TEMPERATURE OF THE FLOOR


qtp = t a + ( —— )

8,92

where: tp = surface temperature of floor, °Cta = ambient temperature, °Cq = specific heat output (upwards) of panel, W/m2

To avoid uncomfortable physiological conditions, the surface temperature ofthe floor should be less than:

• 29°C in continuously occupied environments,• 33°C in bathrooms, showers and swimming pools,• 35°C in perimeter areas or rooms rarely used.

In order to comply with such values, precise limits of the heat output whichcan be transferred by a panel are required.

(5)1

1,1

63

In particular (at ambient temperature = 20°C), the maximum specific outputwhich can be transferred by a panel is:

• qmax = 8,92 . ( 29 – 20 ) 1,1 = 100 W/m2 in continuously inhabited environ-ments.

• qmax = 8,92 . ( 33 – 20 ) 1,1 = 150 W/m2 in bathrooms, showers and swim-ming pools.

• qmax = 8,92 . ( 35 – 20 ) 1,1 = 175 W/m2 in perimeter areas or rooms rarely used.

Multiplying the value of qmax by the area of the panel gives the maximum heatoutput which the panel can transfer to the environment without causing afeeling of discomfort (see item DIMENSIONING OF PANELS, sub-chapterCALCULATION OF PANELS).

64

TEMPERATURE DIFFERENCE OF HEATING FLUID

This is given by the difference between the flow and return temperatures ofthe heating fluid. It is advisable for its value not to be too high in order:

• not to over-reduce the average temperature of the fluid, and thus the heatoutput of the panel;

• to avoid surface temperatures which differ too much from each other, espe-cially with coil panels;

Usually it is advisable to adopt temperature differences below 8 ÷ 10°C.

PANEL FLOW

This is calculated using the formula (13) given in the item FLOW OF HEATFROM A PANEL.

Considering that the maximum flow of a panel is on average between:

– 200 ÷ 220 l/h, for pipes with Di = 16 mm

– 120 ÷ 130 l/h, for pipes with Di = 13 mm

it is possible to determine (although approximately) the maximum heat output(QG.max) which a panel can transfer in relation to its internal diameter. In par-ticular, considering a temperature difference of 8°C, this gives:

• QG.max = ( 200 ÷ 220 ) . 8 . 1,16 = 1.856 ÷ 2.042 W for Di = 16 mm

• QG.max = ( 120 ÷ 130 ) . 8 . 1,16 = 1.114 ÷ 1.206 W for Di = 13 mm

These values can be used as guidance parameters for establishing (as a first ap-proximation) whether a room needs one or more panels.

65

HEAD REQUIRED

This is calculated as shown in the chapter CALCULATION OF PANELS andmust not exceed the preset head. The difference between these two heads is offsetby the panel micrometric regulating valve.

It is advisable that the difference between the preset head and that required(i.e. the value of the offsetting by adjustment) should be at least 200 ÷ 300 mm w.g.It is thus possible (by opening the micrometric valve) to increase the flow throughthe panel and thus its heat output when the operating conditions are more demand-ing than those considered, for example when carpets, which were not provided for,are laid over the flooring, covering large areas.

LENGTH OF THE PANEL

This is calculated using the formula (2) given in the item FLOW OF HEATFROM A PANEL. There are no particular limits with regard to this value. In domestic applications,however, it is advisable not to go beyond the commercial lengths of pipe rolls(120 ÷ 150 metres).

66

FLUID VELOCITY

It is advisable not to accept solutions where the fluid velocity is too low, essen-tially for two reasons: (1) to prevent the formation of air bubbles; (2) to preventthe flow of liquid from becoming laminar, as the panel emission formulae are on-ly valid for turbulent flow.

Normally, velocities higher than 0,1 m/s are acceptable. Higher velocities mustbe provided for when panels are made with reverse gradients (see 1st Handbook, VE-LOCITY OF FLUID).

TOTAL HEAT OUTPUT EMITTED BY A PANEL

This is calculated using the formula (12) given in the item FLOW OF HEATFROM A PANEL. It is used to determine the heat output which must be supplied bythe heat generator.

HEAT OUTPUT EMITTED DOWNWARDS

This is determined by the difference between the total heat output and thattransferred upwards by the panel. It is used to determine the actual thermal re-quirement of the environment situated under the panel.

MEAN HEAT OUTPUT EMITTED UPWARDS FROM ONE METRE OF PIPE

This is calculated by dividing the heat output transmitted upwards by thepanel by its length. It is used to determine the heat contribution of the exposedpipes to the rooms crossed by them.

MEAN HEAT OUTPUT EMITTED DOWNWARDS FROM ONE METRE OF PIPE

This is calculated by dividing the heat output transmitted downwards by thepanel by its length. It is used to determine the heat contribution of the exposedpipes to the rooms underneath.

PRINTER CONFIGURATION

MATERIALS ARCHIVES

GENERAL DATA ARCHIVES

MANAGEMENT OF PROJECT ARCHIVES

CALCULATION PROGRAMME

PROGRAMME FOR THE DIMENSIONINGOF SYSTEMS WITH PANELS

68

P R I N T E R C O N F I G U R A T I O N

This option allows you to set the top and left hand margins of the page layout.It also allows you to carry out a printing test.

– Variable data:• top margin (in lines)• left hand margin (in characters)

– Fixed data:• maximum number of characters per line = 66• maximum number of lines per page = 58

There are three commands managing the inputting of the printed page:

F1 Saves without printing test

F2 Saves with printing test

ESC Exits without saving

69

M A T E R I A L S A R C H I V E S

ARCHIVE OF ZONE VALVES

2-way valves3-way valves

ARCHIVE OF VALVES FOR HEAT EMITTERS

normal valvesvalves with thermostatic option

thermostatic valvesthermoelectric valves

lock shield valves

HEAT EMITTERS ARCHIVE

modular radiatorsnon-modular radiators

convectorsfan coils

70

ZONE VALVE ARCHIVE

Allows you to store and up-date (ingroups of the same commercial series) themain characteristics of the zone valves.

Archive capacity: 20 groups.

The zone valve archive is also used bythe programme for dimensioning sys-tems with manifolds.

ELEMENTS OF THE ARCHIVE

n Archive number (storage code)- maximum value accepted: 20.

c Zone valve type:- 2-way valves,- 3-way valves.

Brandname Brand names of valves

- available space 11 characters.

model Valve group model- available space 14 characters.

KV0,01 (3/4”) Nominal flow rate of valve with Dn = 3/4”, l/h- maximum value accepted: 9999 l/h.- whole numbers only shown on screen.

KV0,01 ( 1” ) Nominal flow rate of valve with Dn = 1”, l/h- maximum value accepted: 9999 l/h.- whole numbers only shown on screen.

71

COMMAND FUNCTIONS

The zone valves archive can be managed by means of the following command functions:

Scroll Enables vertical scrolling on screen.

F1 New valve group Inserts a new valve group.

F2 Modify Modifies the elements of the valve group except the valve type.

F3 Cancel Cancels a valve group.

F5 Go to ... Displays a specific group of valves.

F6 Print Prints the valves in the archive.

F7 Save Saves the up-dates of the archive.

ESC Exit without saving Exits from the archive without saving.

72

ARCHIVE OF VALVES FOR HEAT EMITTERS

Allows you to store and up-date (ingroups of the same commercial series) themain characteristics of the valves forheat emitters.

Archive capacity: 50 groups

The valves archive is also used by theprogramme for dimensioning systemswith manifolds.



c Valve types:- 1 normal valves,- 2 valves with thermostatic option- 3 thermostatic valves,- 4 thermoelectric valves,- 5 lock shield valves.

Brandname Brand names of valves


Model Valve group model- available space 11 characters.



73

COMMAND FUNCTIONS

The valves for heat emitters archive can be managed by means of the following com-mand functions:

Scroll Enables vertical scrolling

F1 New valve group Inserts a new group of valves.

F2 Modify Modifies the elements of the group of valvesexcept for the relevant types.

F3 Cancel Cancels a group of valves.

F5 Go to ... Displays a specific group of valves.

F6 Print Prints the valves in the archive.



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HEAT EMITTERS ARCHIVE

Allows you to store and up-date themain characteristics of radiators, con-vectors and fan coils.

Archive capacity: 200 heat emitters.

N.B.:This archive is also used by the programme for dimensioning systems withmanifolds and makes it possible to store three types of heat emitter- radiators;- convectors;- fan coils.Only radiators are already recognised and used by the programme for the di-mensioning of panels.

All the archive elements are presented below, including those for convectors and fancoils.



c Heat emitter types:- 1 modular radiators,- 2 non-modular radiators,- 3 convectors,- 4 fan coils.

Brandname Brand names of heat emitters


Model Heat emitter model- available space 8 characters.

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tm Mean temperature of heating fluid, °C- max. accepted value: 99 °C.- whole numbers only shown on screen.

Qn (*) Nominal heat output, W- max. accepted value: 9999 W.- whole numbers only shown on screen.

l Width of heat emitter, mm- size required only for non-modular heat emitters.- max. accepted value: 9999 mm.- whole numbers only shown on screen.

m Width of boss, mm- size required only for modular heat emitters.- max. accepted value: 999 mm.- whole numbers only shown on screen.

h Height of heat emitter, mm- max. accepted value: 9999 mm.- whole numbers only shown on screen.

Gn (*) Nominal flow rate of heat emitter, l/h- required only for convectors and fan coils.- max. accepted value: 9999 l/h.- whole numbers only shown on screen.

Hn (*) Heat emitter pressure differential, mm w.g.- size required only for convectors and fan convectors.- max. accepted value: 9999 mm w.g.- whole numbers only shown on screen.

vol Water contained by basic element (modular heat emitters) or bythe heat emitter (non modular heat emitters), l- max. accepted value: 99,99 l.- value shown on screen to 2 decimal places.

(*) Definitions of Qn, Gn, Hn

Qn Nominal heat output: this is the heat output which the heat emitter ex-changes with the external environment in test conditions

Gn Nominal flow rate: this is the flow rate required to determine the nomi-nal heat output of the heat emitter.

Hn Nominal pressure differential: this is the differential pressure requiredto pass the nominal flow rate through the heat emitter.

76

COMMAND FUNCTIONS

The heat emitters archive can be managed by means of the following command functions:

Scroll Enables vertical scrolling.

F1 New heat emitter Inserts a new heat emitter.

F2 Modify Modifies the elements of the group of heatemitters except for the relevant types.

F3 Cancel Cancels a group of heat emitters.

F5 Go to ... Displays a specific group of heat emitters.

F6 Print Prints the heat emitters in the archive.



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MAIN PARAMETERS ARCHIVE

DATA ANALYSIS

GRAPHICAL REPRESENTATION

G E N E R A L D A T A A R C H I V E S

DATA ANALYSIS


DATA ANALYSIS


MANIFOLD CHARACTERISTICSARCHIVE

PIPES AND CENTRE DISTANCEARCHIVE

78

MAIN PARAMETERS ARCHIVE

This makes it possible to predetermine the following parameters to be pro-posed as default for the dimensioning of the system:

1. Preset head to panel- values accepted from 500 to 5000 mm w.g.- whole numbers only shown on screen.

2. Project maximum temperature- values accepted from 30 to 60°C.- whole numbers only shown on screen.

3. Ambient temperature- values accepted from 10 to 25°C.- whole numbers only shown on screen.

4. Zone valve group code- values accepted from 0 to 20.

5. Underlying ground or room temperature- values accepted from -15 to 20°C.- whole numbers only shown on screen.

6. Thermal resistance of floor- values accepted from 0,000 to 0,150 m2K/W.- values shown on screen to 3 decimal places.

7. Thickness of slab- values accepted from 2 to 20 cm.- whole numbers only shown on screen.

8. Thermal resistance under panel- values accepted from 0,500 to 3,500 m2K/W.- values shown on screen to 3 decimal places.

9. Minimum velocity of fluid in panels- values accepted from 0,05 to 0,40 m/s.- values shown on screen to 2 decimal spaces.

10. Valves for heat emitters group code- values accepted from 1 a 50.

11. Lockshield group code- values accepted from 1 to 50.

12. Reference heat emitter code- values accepted from 0 to 200.

13. Temperature difference of heat emitter- values accepted from 2 to 10°C.- whole numbers only shown on screen.

14. Maximum velocity of carrying fluid in heat emitter pipes- values accepted from 0,5 to 1,5 m/s.- values shown on screen to 2 decimal spaces.

79

80

MANIFOLD DATA ARCHIVE

This makes it possible to predetermine the main characteristics of the mani-fold and the relative on-off and regulating valves.

1. Brand name of manifold- available space 10 characters.

2. Manifold identifying symbol- available space 10 characters.

3. Internal diameter of manifold- values accepted from 20 to 60 mm.- values shown on screen to 1 decimal place.

4. KV0,01 panel manual on-off valve- maximum value accepted 9999 l/h.- whole numbers only shown on screen.

5. KV0,01 panel automatic on-off valve- maximum value accepted 9999 l/h.- whole numbers only shown on screen.

6. Type of on-off valve proposed:- 1 manual,- 2 automatic.

7. KV0,01 micrometer regulating valve- maximum value accepted 999,9 l/h.- values shown on screen to 1 decimal place.

81

DATA ARCHIVE FOR PIPES AND CENTRE DISTANCES

This makes it possible to predetermine the main characteristics of the pipesand the possible fitting centre distances.

1. Brand name of pipe- available space 10 characters.

2. Pipe material code: 1 PEX - 2 PB - 3 PP

3. External diameter of pipe for panels- values accepted from 15 to 22 mm.- values shown on screen to 1 decimal place.

4. Internal diameter of pipe for panels- values accepted from 10 to 18 mm.- values shown on screen to 1 decimal place.

5. External diameter of pipe for heat emitters- values accepted from 12 to 20 mm.- values shown on screen to 1 decimal place.

6. Internal diameter of pipe for heat emitters- values accepted from 8 to 16 mm.- values shown on screen to 1 decimal place.

7. Grid of available centre distances- values accepted from 7,5 to 40 mm.- values shown on screen to 1 decimal place.

N.B.:The grid must be supplemented with the entry (from the smallest centredistance) of the five centre distances provided for. For this purpose, the supportvalues can also be entered, thus avoiding accepting the relative solutions.

82

P R O J E C T A R C H I V E M A N A G E M E N T

This part of the programme makes it possible to store and recall the data(files) for each project processed.The files are saved in a suitable directory and can be opened or recalled with the op-tions specified below.

CHARACTERISTICS OF THE ARCHIVE CONTAINING THE PROJECT FILES

• Resides on floppy disk to be inserted in drive A.

• Initialised by programme with suitable procedure.

• Maximum capacity 70 projects (actual capacity depends on capacity of floppydisk and size of project files).

MAIN OPTIONS FOR FILE MANAGEMENT

• Opens a new project file on the floppy archive.

• Stores the principal recognition data and location of system.

• Checks general data archives.

• Starts up calculation programme.

• Calls up an existing project file on floppy.

• Checks and corrects the client's recognition data andsystem location.

• Starts up calculation programme, indicating last mani-fold calculated.

• Deletes a project file.

N New

V Old

E Delete

83

C A L C U L A T I O N P R O G R A M M E

First PartMANIFOLD MANAGEMENT AND PROCESS PRINTING

Provides:

manifold dimensioning start-up, general data archive check, modification of main parameters, examination of data on each manifold, modification of data on each manifold, print out of accepted solutions, print out of materials calculation.

Second partMANAGEMENT OF BRANCH CIRCUITS

Provides:

dimensioning of branch circuits, modification of branch circuit data, examination of data and solutions accepted, storage of solutions accepted.

Third partSELECTION OF SOLUTIONS PREPARED

For each branch circuit, provides:

acceptance of required solution, variation of project data, request for new dimensioning.

84

N New manifold

MANIFOLD MANAGEMENT AND PROCESS PRINTING

The following command functions are available for this first part of the pro-gramme:

Dimensions a new manifold.

E Examine manifold

Examines the data (project and calculation) relating to a specific manifold.

M Modify manifold

Modifies the project data or accepted solutions for the branch circuitsrelating to a specific manifold.

F1 General data

- Checks the data of the general archives.

- Also varies the data of the main parameters. However, it is not possible (oncethe project has started) to vary the data on manifold, pipes and centre distances.

F6 Print project

Prints the solutions accepted and the metric calculation.

F10 End of task

Exits from calculation programme.

85

P Panel

MANAGEMENT OF BRANCH CIRCUITS

The following command functions are available for this part of the pro-gramme:

Dimensions a panel.

R Heat emitter

Dimensions a heat emitter and the relevant circuit.

E Examination of data not on screen

Examines the data (for the panels or heat emitters) not normally shownon screen.

M Modifies project data

Varies project data of branch circuits.

C Cancels panel/heat emitter

Cancels a panel or heat emitter.

Esc Exits

Abandons dimensioning the manifold.

F10 End of calculation

– Stores the solutions relating to the circuits dimensioned (on the pro-ject files).

– Also stores these solutions several times so that the materials in thesystem with equal branches can be calculated more easily: for example inmulti-storey buildings or detached houses.

86

PANEL DIMENSIONING

This is done in three stages:

– project data acquisition,

– development of calculations,

– presentation of data processed.

ACQUISITION OF PROJECT DATA

The project data required can be broken down into two groups:

– data requested by programme: - data relating to the manifold,- data relating to the panel.

– data derived from the archives.

Data required relating to the manifold

Used to define the conditions on the basis of which the manifold feeds itsbranches (panels or heat emitters). Data required:

Hpann (*) Preset head on panel- values accepted from 500 to 5000 mm w.g.- whole numbers only shown on screen.

tmax (*) Maximum project temperature- values accepted from 30 to 60°C.- whole numbers only shown on screen.

cvz (*) Zone valve group code- values accepted from 0 to 20.- for manifolds with no zone valve, put cvz=0.

N.B.This data is only required when dimensioning of a new manifold is started.

(*) Data proposed as default on the basis of the predefined general parameters.

87

Data required regarding the panel

Used to identify the geometrical characteristics of the panel and the condi-tions on the basis of which it must be dimensioned. Data required:

Room Purpose of the room used- available space 12 characters.

Q Heat output required- maximum value accepted 9999 W.- whole numbers only shown on screen.

S Total area of panel (including peripheral zone)- maximum value accepted 99,9 m2.- value shown on screen to 1 decimal place.

Szp (1) Area of peripheral zone- maximum value accepted 9,9 m2.- value shown on screen to 1 decimal place.

La Length of manifold-panel piping- maximum value accepted 99 m.- whole numbers only shown on screen.

ta (*) Ambient temperature- values accepted 10 to 25°C.- whole numbers only shown on screen.

Rp(*) Thermal resistance of floor- values accepted from 0,000 to 0,150 m2K/W.- value shown on screen to 3 decimal places.

sm(*) Thickness of slab- values accepted from 2 to 20 cm.- whole numbers only shown on screen.

Rs(*) Thermal resistance under panel- values accepted from 0,500 to 3,500 m2K/W.- value shown on screen to 3 decimal places.

vi (*) Proposed on-off valves- values accepted: 1 and 2.

N.B.(1):The value of Szp (peripheral zone area) cannot be greater than 40% of S (totalpanel area).


88

DEVELOPMENT OF CALCULATIONS

Having acquired the project data, the programme prepares the solutions relat-ing to each centre distance of the available grid (see PIPES AND CENTRE DIS-TANCES ARCHIVE) and breaks down these solutions into two categories: accept-able and unacceptable.

Acceptable solutions

The programme accepts all solutions where the cases specified below do notarise.

Unacceptable solutions

The programme does not accept the solutions where at least one of the fol-lowing conditions arises:

– Qmax (I) ‹ Q

The maximum heat output which can be transferred by the panel (in relation tothe centre distance in question) is not able to handle the output required: thismeans that the panel is under-dimensioned (see DIMENSIONING OF PANELS)

(-) is the symbol on screen showing unacceptability.

– Qmin (I) › Q

The minimum heat output which can be transferred by the panel (in relation tothe centre distance in question) is too high in relation to the output required; thismeans that the panel is over-dimensioned (see DIMENSIONING OF PANELS).

(+) is the symbol on screen showing unacceptability.

– H (I) › Hpann

The head required (in relation to the centre distance considered) is too high in re-lation to that pre-set (see DIMENSIONING OF PANELS).

(H) is the symbol on screen showing unacceptability.

89

PRESENTATION OF THE DATA PROCESSED

For each centre distance available, the programme presents the solutions pre-pared on screen and (where acceptable) the following sizes:

tp Surface temperature of floor

tzp Surface temperature of peripheral zone

dt Temperature difference between fluid inlet and outlet temperatures

L Total length of pipe

v Velocity of fluid

In addition, the programme indicates, in flashing characters, cases where the velocity ofthe fluid is lower than the limit defined in the GENERAL PARAMETERS ARCHIVE.

The main commands for selecting the proposed solutions are shown in thechapter “SELECTION OF THE SOLUTIONS PROCESSED”.

90

CALCULATION OF HEAT EMITTERS

This is carried out in three stages:

– acquisition of project data,

– development of calculations,

– presentation of data processed.

ACQUISITION OF PROJECT DATA

The project data required can be broken down into two groups:

– data requested by the programme: - data regarding the manifold,- data regarding the heat emitters.

– data derived from the archives.

Data requested regarding the manifold

This is used to define the conditions on the basis of which the manifold feedsits branches and are the same required for the dimensioning of the panels.

Data requested regarding the heat emitter

Used to identify the type of heat emitter and the conditions on the basis ofwhich it must be dimensioned. Data requested:

Room Purpose of room served- available space 12 characters.

Q Heat output required- maximum value accepted 9999 W.- whole numbers only shown on screen.

91

La Length of manifold-heat emitter pipes- maximum value accepted 99 m.- whole numbers only shown on screen.

r (*) Heat emitter code- values accepted from 1 to 200.

ta (*) Ambient temperature- values accepted from 10 to 25°C.- whole numbers only shown on screen.

dt (*) Temperature difference input- values accepted from 1 to 20°C.- whole numbers only shown on screen.

cv(*) Code of valve group for heat emitters- values accepted from 1 to 50.

cd(*) Code of lock shield valve group for heat emitters- values accepted from 1 to 50.

vi (*) Proposed on-off valves:- values accepted: 1 and 2.

DEVELOPMENT OF CALCULATIONS

When the project data is acquired, the programme prepares the requested so-lution on the basis of the temperature difference input and considers these so-lutions acceptable only if a head lower than that available at the manifold con-nections is requested.If the head is too high, the temperature difference input must be increased.In this way the flow through the heat emitter, and thus the requested relative head,is reduced.

PRESENTATION OF THE DATA PROCESSED

The programme presents the solution processed on screen and indicates inflashing characters cases where the fluid velocity is above the limit defined in theGENERAL PARAMETERS ARCHIVE.The main commands permitting acceptance or revision of the proposed solu-tion are given in the following chapter.


92

1÷5 Solutions to be accepted

SELECTION OF THE SOLUTIONS PROCESSED

The following command functions are available for selection of the solutionsprocessed:

This function is reserved for the panels and makes it possible (withinthe scope of the possible solutions) to select the panel configurationconsidered most appropriate.

Exec Accepts

This function is reserved for the heat emitters and makes it possibleto accept the proposed solution.

V Vary data

Makes it possible to vary the project data and carry out new dimen-sioning (for both panels and heat emitters).

Esc Exits without saving

Cancels all data of the branch circuit in question and permits dimensioning from zero.

EXAMPLE OF CALCULATION

94

Example:

Dimension a panel system for zone heating of dwellings represented in the page alongside. The fol-lowing are considered:

– ta = 20°C ambient temperature

– ts = 5°C temperature of basement

– heating requirement:

Room n 2nd floor 1st floor mezzanineW W W

- living 1 2.900 2.420 2.420- kitchen 2 1.180 990 990- bathroom A 3 610 520 520- bedroom A 4 1.430 1.150 1.150- bedroom B 5 1.050 770 770- bathroom B 6 310 250 250- corridor 7 180 90 90

N.B.: for rooms in the mezzanine, the heat losses of floor have not been taken into consideration(see sub-chapter under DIMENSIONING OF PANELS).

– structure of floor slabs:- ceramic, s = 0,8 cm- slab, s = 8,0 cm- polystyrene insulation, ..................... thickness to be defined- brick floor slab, s = 20,0 cm- plaster, s = 1,5 cm

Solution:

The Caleffi Handbooks 99 software is used, and on the basis of this configuration, the system is bro-ken down dimensionally into the following phases:

– Analysis and selection of data regarding the main parameters archive

– Selection of manifold and valves for control and regulation of panels

– Selection of pipes and available centre-to-centre distances

– Notes and conventions assumed

– Activation of project file

– Dimensioning of branches and manifolds on 2nd floor

– Dimensioning of branches and manifolds on 1st floor

– Dimensioning of branches and manifolds on mezzanine

– Printing calculation and symbols

– Dimensioning distribution network

– Calculation of total heat output

95

96

Analysis and selection of data relating to the main parameters archive

– Preset head at panel connections

The main system network is dimensioned by the practical calculation method illustrated underSIMPLE CIRCUITS, 2nd Handbook.On the basis of this method (the variation in head from floor to floor is considered on average tobe 100 mm w.g.) and in relation to the terms of the item DIMENSIONING THE PANELS (sub-chapter PRESET HEAD), the following is assumed:

Hpann = 1.800 mm w.g. (2nd floor)Hpann = 1.900 mm w.g. (1st floor)Hpann = 2.000 mm w.g. (mezzanine)

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– Thermal resistance of floor

This can be calculated using formula (3) or the tables given under DIMENSIONING OF PANELS,sub-chapter THERMAL RESISTANCE OF FLOOR.The table on ceramics, for a thickness of 0.8 cm, gives: Rp = 0,008 m2K/W.

– Maximum design temperature

This is determined using Table 3 given under the item DIMENSIONING OF PANELS, sub-chapterTHERMAL RESISTANCE OF FLOOR. On the basis of this table:

- where: Rp = 0,008 m2K/W,- considering values of qmax not greater than 95÷100 W/m2,- also considering that a low design temperature makes it possible to use a condensing boiler orheat pump also,

it is assumed that : tmax = 40°C.

– Zone valves

Caleffi model 6480/6460 3-way zone valves are used with the following characteristics:- 3/4” valve KV0,01 = 1.200 l/h- 1” valve KV0,01 = 3.000 l/h

These valves are already on file with the code number: cvz = 1.

– Thickness of the slab above the pipes

This is obtained by subtracting the outer diameter of the pipes from the thickness of the slab. In the case in question, considering pipes of outer diameter 2 cm and slab thickness 8 cm, thefollowing is obtained:

s = 8,0 - 2,0 = 6,0 cm.

– Thermal resistance under panel

To limit the heat output transferred downwards by the panels from the mezzanine and from the2nd floor panels (the latter are the panels which have to produce the greatest heat output) the fol-lowing thicknesses of insulating material are assumed:

- 2nd floor insulating material thickness = 4,0 cm- 1st floor insulating material thickness = 2,0 cm- mezzanine insulating material thickness = 4,0 cm

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The thermal resistance under the panel can be calculated using the formula (4) or with the tablesgiven under the heading DIMENSIONING OF PANELS, sub-chapter THERMAL RESISTANCEUNDER PANEL.In the case in question, from the table regarding brick floor slab and polystyrene insulation, forthe thicknesses of insulation specified above, the following is obtained:

Rs = 1,633 m2K/W (2nd floor)Rs = 1,061 m2K/W (1st floor)Rs = 1,633 m2K/W (mezzanine)

– Minimum velocity of fluid in panels

The following is taken (see relevant sub-chapter under the heading DIMENSIONING OF PANELS):

vmin = 0,05 m/s.

– Valves for heat emitters

Caleffi model 338/sq valves with thermostatic option are used with the following characteristics:- 3/8” valve KV0,01 = 222 l/h- 1/2” valve KV0,01 = 270 l/h

These valves are already on file with the code number cv = 2.

– Lock Shield Valves for heat emitters

Caleffi model 342/sq lock shield valves are used with the following characteristics:- 3/8” valve KV0,01 = 242 l/h- 1/2” valve KV0,01 = 399 l/h

These valves are already on file with the code number cd = 10.

– Reference heat emitter

A radiator of the following characteristics is taken as the reference heat emitter (i.e. to be pro-posed as default):

- trade name, OMEGA

- model, 680/4- mean test temperature, 80°C- rated heat output, 145 W- width, 60 mm- height, 680 mm- water content, 1,10 l

This heat emitter is already on file with the code number: r = 1.

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– Temperature difference across heat emitter

The default temperature difference for dimensioning the integrated heat emitters is:

∆∆t = 4°C.

This value generally provides a good compromise between two different requirements: (1) not toreduce the average temperature, and thus the output of the heat emitter excessively; (2) not tocall for excessively high flows and thus heads greater than available.

– Maximum velocity of flow in the pipes of the heat emitters

The following is taken (see relevant sub-chapter under the heading DIMENSIONING OF SYS-TEMS WITH MANIFOLDS):

vmax = 0,75 m/s

On the basis of the project data and the choices made, the following values are input in the GENER-AL PARAMETERS file:

N.B.: The preset head, the temperature of the room below and the thermal resistance under thepanel refer to the last floor, in other words the floor from which the dimensioning of the sys-tem starts.

GENERAL PARAMETERS FILE

Preset head at panel [mm w.g.] ............................ 1800Maximum design temperature [°C] ...................... 40

Ambient temperature [°C] ................................... 20

Zone valve group code ......................................... 1

Ambient temperature below [°C] ......................... 20Floor thermal resistance [m2K/W] ....................... 0,008Slab thickness above pipes [cm] ........................... 6Thermal resistance under panels [m2K/W] .......... 1,633Min. Vel. heating fluid (panels) [m/s] .................. 0,05

Heat emitters valve group code ............................ 2Lock shield valve group code ................................ 10Reference heat emitter code ................................. 1Project temperature difference (heat emitter) [°C] .... 4Min. Vel. heating fluid (heat emitter) [m/s]............ 0,75

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Selection of manifold and valves for control and regulation of panels

The following are used:

- flow manifold Caleffi model 666 with relevant micrometric regulating valves,- return manifold Caleffi model 667 with relevant manual shut-off valves.

On the basis of the choices made (type of manifold and valves) the following values are input in theMANIFOLD CHARACTERISTICS archive:

Selection of pipes and available centre-to-centre distances

– Pipes

Pipes are used having the following characteristics:

- trade name, SIGMA

- material, PEX

- De = 20 mm, Di = 16 mm, for making panels, - De = 15 mm, Di = 10 mm, for connecting heat emitters.

MANIFOLD CHARACTERISTICS ARCHIVE

Trade name of manifold ................................ CALEFFIIdentifying logo ............................................ 666/667

Internal diameter of manifold ............. [mm] 31,0

Panel manual shut-off valve KV [ 0,01 bar] .. 287Panel automatic control valve KV [ 0,01 bar] 287Types of control valve proposed: 1 manual, 2 automatic 1

Micrometric reg. Valve KV [ 0,01 bar]: curve 1 6,0” ” ” ” : ” 2 18,0” ” ” ” : ” 3 21,0” ” ” ” : ” 4 27,0” ” ” ” : ” 5 31,0” ” ” ” : ” 6 42,0” ” ” ” : ” 7 53,0” ” ” ” : ” 8 70,0” ” ” ” : ” 9 89,0” ” ” ” : ” 10 115,0

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– Grid of available centre-to-centre distances

The following 5 centre-to-centre distances are used (see explanatory note in the item GENERAL DA-TA ARCHIVES, sub-chapter DATA ARCHIVES REGARDING PIPES AND CENTRE-TO-CENTREDISTANCES):- 7,5 cm- 15,0 cm- 22,5 cm- 30,0 cm- 37,5 cm

On the basis of the selections made (type of pipes and grid of centre-to-centre distances) the follow-ing values are input in the PIPES AND CENTRE-TO-CENTRE DISTANCES archive.

Notes and conventions assumed

1. The manifolds and branches are dimensioned starting from the last floor. This makes it possible:

- to calculate the heat output transferred to the rooms of the underlying floor (see item DIMEN-SIONING OF PANELS, sub-chapter HEAT OUTPUT REQUIRED).

- to check that the pre-set project temperature can provide the heat output required. The secondand last storey is in fact thermally more demanding as it has a greater loss area and does not re-ceive heat from the floor slab of the storey above.

2. The heating contribution of the panels placed on the upper storey is taken as half of thatactually transferred. This procedure - combined with good insulation under the panels - guar-antees valid thermal conditions even when the system in the rooms above is turned off.

PIPES AND CENTRE DISTANCES ARCHIVE

Pipe trade name ............................................ SIGMAMaterial code (1 - PEX, 2 - PB, 3 - PP) ... 1

External diameter pipe for panels [mm] 20,0Internal diameter pipe for panels [mm] 16,0

External diameter pipe for heat emitters. [mm] 15,0Internal diameter pipe for heat emitters. [mm] 10,0

Grid of available 1st centre dist. [cm] 7,5centre to centre distances: 2nd centre dist. [cm] 15,0

3rd centre dist. [cm] 22,54th centre dist. [cm] 30,05th centre dist. [cm] 37,5

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3. The column and manifold positions shown below are used:

Activation of project file

The project file is started up by inputting: Project file name: PAN-ESClient name: AABuilding location: BB

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Dimensioning of the branches and manifolds on 2nd floor

The programme shows as general data for the first manifold:

Hpann = 1.800 mm w.g.tmax = 40°Ccvz = 1

These values are accepted and the dimensioning is started from the first branch.

Living room, room No. 1, 2nd floor

The high heat output required (2,900 W) means that two panels should be used (see item DIMEN-SIONING OF PANELS, sub-chapter PANEL FLOW). Therefore the following is proposed:

Branch 1 - Living room 1A: Q = 2.900 / 2 = 1.450 WS = 34 / 2 = 17 m2

La = = 1 m other data as proposed by the programme as default

solutions relating to the data proposed:

Solution No. 2 is accepted. The same data is proposed and the same solution is also achievedfor branch No. 2 - Living room 1B

Kitchen, room No. 2, 2nd floor

The heat output required (1,180 W) and the available area (14 m2 ) are such that a single panelwill be sufficient. Therefore the following is proposed:

Branch 3 - Kitchen 2: Q = 1.180 WS = 14 m2

La = 8 m other data as proposed by the programme as default


Solution No. 2 is accepted.

n I C tp tzp dt L v1 7,5 27,8 - 10,5 228 0,182 15,0 27,8 - 6,0 114 0,32/ 22,5 (-)/ 30,0 (-)/ 37,5 (-)

n I C tp tzp dt L v1 7,5 27,7 - 11,0 195 0,142 15,0 27,7 - 6,0 101 0,26/ 22,5 (-)/ 30,0 (-)/ 37,5 (-)

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Bathroom, room No. 3, 2nd floor

Considering a useful area of 3m2, the maximum heat output (Qmax) which a panel can transfer toa bathroom is:

Qmax = qmax . S = 150 . 3 = 450 W

This output is lower than required (610 W) and an additional heat emitter must therefore beprovided.

For dimensioning the panel, it is assumed as an initial approximation that it can transfer itsmaximum output, so the following is proposed

Branch 4 - Bathroom 3A: Q = 450 WS = 3 m2


Processing this data does not give an acceptable solution. Therefore the panel is recalculated, re-ducing the output value required. For example, putting Q = 360 W makes solution No. 1 ac-ceptable, in other words the solution which provides for a centre-to-centre distance of 7,5 cm.

The following is proposed for dimensioning the heat emitter:

Branch 5 - Bathroom 3B: Q = 610 - 360 = 250 WLa = 12 m other data as proposed by the programme as default

The solution prepared by the programme, which provides for a heat emitter consisting of 8elements of model 680/4 (defined as default) is accepted

Bedroom, room No. 4, 2nd floor

The heat output required (1,430W) and the available area (20 m2) mean that a single panel issufficient. The following is therefore proposed

Branch 6 - Kitchen 4: Q = 1.430 WS = 20 m2




n I C tp tzp dt L v1 7,5 26,6 - 14,0 273 0,132 15,0 26,6 - 10,5 139 0,183 22,5 26,6 - 5,5 95 0,34/ 30,0 (-)/ 37,5 (-)

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Bedroom, room No. 5, 2nd floor

The heat output required (1,050W) and the available area (20 m2) mean that a single panel issufficient. The following is therefore proposed

Branch 7 - Bedroom 5: Q = 1.050 WS = 20 m2




Bathroom room No. 6, 2nd floor

The heat output required (310 W) and the available area (2.8 m2) mean that a single panel is suf-ficient. The following is therefore proposed

Branch 8 - Bathroom 6: Q = 310 WS = 2,8 m2



Solution No. 1 is accepted

Corridor, room No. 7, 2nd floor

The heat given off by the pipes leading to other panels is considered sufficient here.

The solutions prepared are accepted twice to confirm the calculation of the materials forboth the dwellings on the second floor.A drawing follows, plus the print-outs which show the results obtained (see key to symbols used atthe end of the panel dimensioning).

n I C tp tzp dt L v1 7,5 25,0 - 17,5 275 0,082 15,0 25,0 - 15,5 141 0,093 22,5 25,0 - 12,5 97 0,114 30,0 25,0 - 8,5 75 0,16/ 37,5 (-)

n I C tp tzp dt L v1 7,5 29,9 - 3,5 43 0,12/ 15,0 (-)/ 22,5 (-)/ 30,0 (-)/ 37,5 (-)

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Dimensioning of the branches and manifolds on 1st floor

For the GENERAL DATA function, enter: Hpann = 1.900 mm w.g. (previous val. 1.800)Rs = 1,061 m2K/W (previous val. 1,633)

The dimensioning of the second manifold is then required, and, accepting the relevant data offeredas default, the dimensioning of the branches is commenced.

Living room, room No. 1, 1st floor


Branch 1 - Living room 1A: Q = ( 2.420 / 2 ) - ( 134 / 2 ) = 1.143 W(1)

S = 34 / 2 = 17 m2


Of the solutions relating to the data proposed, No. 3 is accepted (I = 22.5 cm). The same da-ta is proposed and the same solution is also accepted for branch No. 2 - Living room 1 B.

Kitchen, room No. 2, 1st floor

The heat output required and the available area are such that a single panel will be sufficient.Therefore the following is proposed:

Branch 3 - Kitchen 2: Q = 990 - ( 109 / 2 ) = 936 W(1)

S = 14 m2


Of the solutions relating to the data proposed, No. 3 is accepted (I = 22,5 cm).

Bathroom, room No. 3, 1st floor

Same as for 2nd floor bathroom, dimensioning a panel with Q = 360 W and I = 7,5 cm. For dimensioning of the heat emitter, the following is proposed

Branch 5 - Bathroom 3B: Q = 520 - 360 - ( 33 / 2 ) = 144 W(1)

La = 12 mother data as proposed by the programme as default

The solution proposed by the programme is accepted, which provides for a heat emitterconsisting of 5 elements, model 680/4 (defined as default).

(1) For the calculation of Q, see: Notes and conventions used.

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Bedroom, room No. 4, 1st floor

The heat output required and the available area mean that a single panel is sufficient. The fol-lowing is therefore proposed:

Branch 6 - Bedroom 4: Q = 1.150 - ( 132 / 2 ) = 1.084 W(1)

S = 20 m2


Of the solutions relating to the data proposed, No. 4 is accepted. (I = 30,0 cm).

Bedroom, room No. 5, 1st floor


Branch 7 - Bedroom 5: Q = 770 - ( 97 / 2 ) = 722 W(1)

S = 20 m2


Only Solution No. 5 was considered acceptable (I = 37.5 cm). However, it is advisable toadopt a smaller centre-to-centre distance (see item DIMENSIONING OF PANELS, sub-chapterCENTRE-TO-CENTRE DISTANCES). For this purpose, the surface (S) of the panel is reduced.

In particular, S = 14 m2 and the new solution No. 4 (I = 30,0 cm) is accepted.

Bathroom, room No. 6, 1st Floor


Branch 8 - Bathroom 6: Q = 250 - ( 29 / 2 ) = 236 W(1)

S = 2,8 m2



Corridor, room No. 7, 1st floor

The heat given off by the pipes leading to the other panels is considered sufficient here.

The solutions prepared are accepted twice to confirm the calculation of the materials forboth the dwellings on the first floor. A drawing follows, plus the print-outs which show the re-sults obtained (see key to symbols used at the end of the panel dimensioning).

(1) For calculation of Q, see: Notes and conventions used.

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Dimensioning of branches and manifolds on mezzanine

For the GENERAL DATA function, enter: Hpann = 2.000 mm w.g. (previous val. 1.900)Rs = 1,633 m2K/W (previous val. 1,061)ts = + 5°C (previous val. +20)

The dimensioning of the third manifold is then required, and, accepting the relevant data offered asdefault, the dimensioning of the branches is commenced.

Living room, room No. 1, mezzanine


Branch 1 - Living room 1A: Q = ( 2.420 / 2 ) - ( 163 / 2 ) = 1.129 W(1)

S = 34 / 2 = 17 m2


Of the solutions relating to the data proposed, No. 3 is accepted (I = 22,5 cm). The samedata is proposed and the same solution is also accepted for branch No. 2 - Living room 1 B

Kitchen, room No. 2, mezzanine

The heat output required and the available area are such that a single panel will be sufficient.Therefore the following is proposed:

Branch 3 - Kitchen 2: Q = 990 - ( 133 / 2 ) = 924 W(1)

S = 14 m2



Bathroom, room No. 3, mezzanine

Same as for 2nd floor bathroom, dimensioning a panel with Q = 360 W e I = 7,5 cm. For dimensioning of the heat emitter, the following is proposed

Branch 5 - Bathroom 3B: Q = 520 - 360 - ( 51 / 2 ) = 135 W(1)

La = 12 mother data as proposed by the programme as default

The solution proposed by the programme is accepted, which provides for a heat emitterconsisting of 5 elements, model 680/4 (defined as default).


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Bedroom, room No. 4, mezzanine


Branch 6 - Bedroom 4 Q = 1.150 - ( 154 / 2 ) = 1.073 W(1)

S = 20 m2



Bedroom, room No. 5, mezzanine

Same as for 1st floor bathroom, a reduced area of 14 m2 is considered. The following is therefore proposed:

Branch 7 - Bedroom 5: Q = 770 - ( 103 / 2 ) = 719 W(1)

S = 14 m2



Bathroom, room No. 6, mezzanine


Branch 8 - Bathroom 6 Q = 250 - ( 34 / 2 ) = 233 W(1)

S = 2,8 m2



Corridor, room No. 7, mezzanine

The heat given off by the pipes leading to the other panels is considered sufficient here.

The solutions prepared are accepted twice to confirm the calculation of the materials forboth the dwellings on the mezzanine floor.A drawing follows, plus the print-outs which show the results obtained (see key to symbols used atthe end of the panel dimensioning).


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Dimensioning of distribution network

The distribution network is dimensioned using the method of constant linear head losses, taking as aguide value r = 10 mm w.g./m and using Table 4 in the 1st Handbook, item STEEL PIPES.

The following is thus obtained:

– 2nd floor riser - manifold connection pipes G =1.478 l/h ø = 1 1/4”

– 1st floor riser - manifold connection pipes G =1.081 l/h ø = 1”

– mezzanine riser - manifold connection pipes G =1.108 l/h ø = 1”

– 1st floor - 2nd floor riser section G = 1.478 · 2 = 2.956 l/h ø = 1 1/2”

– 1st floor - mezzanine riser section G = 2.956 + 1.081 · 2 = 5.118 l/h ø = 2”

– mezzanine - heating centre riser section G = 5.118 + 1.108 · 2 = 7.334 l/h ø = 2 1/2”

The head obtained at the base of the circuit is determined (see practical methods, 1st Handbook) byadding together:

• the head required upstream from the last manifold (Hzone);

• the continuous loss of head from the circuit (Hcont) considered conventionally as equal tothe product of:- r = guide value of linear constant head loss,- l = circuit length;

• the localised head losses (Hloc) taken as equal to 60% of the continuous head loss.

The result is thus: - Hzone (2nd floor) = 1.893 mm w.g.(see 2nd floor manifold print-out)

- Hcont = l · r = (la + lc + lo ) · r = 40 · 10 = 400 mm w.g.

where: la = 12 m length 2nd floor manifold-riser connecting pipelc = 12 m length riser pipes

and assuming:lo = 16 m length heating centre - riser connecting pipes

- Hloc = 400 · 0,6 = 240 mm w.g.

The head obtained at the base of the circuit is thus:

H = 1.893 + 400 + 240 = 2.533 mm w.g.

Calculation of total heat output

The total heat output emitted by the panels (upwards and downwards) and the heat emitters is cal-culated by adding together the heat outputs given off by the emitters of each manifold (see relevantprint-outs). The result is thus:

- Qtot = 8.141 · 2 + 6.576 · 2 + 7.040 · 2 = 43.514 W

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Project File: Date:

Client:

Installer:

Systemlocation:

Manifold:

Piping: panels: D e = — mm D i = — mm

Heat emitters: D e = — mm D i = — mm

Centre-to-: I 1 = 7,5 I 2 = 15,0 I 3 = 22,5 I 4 = 30,0 I 5 = 37,5centre

I 1 = 5,0 I 2 = 10,0 I 3 = 15,0 I 4 = 20,0 I 5 = 30,0distances

I 1 = — I 2 = — I 3 = — I 4 = — I 5 = —

Notes:

PANEL SYSTEMS DATA SURVEY

CALEFFI HANDBOOKS SOFTWARE

Project File:

Manifold n:

Hpann: mm w.g.

tmax: °C

cvz:

PANEL DATA SURVEY

N Room Qdisp Q (±) Q Sloc Span Szp La ta ts Rp sm Rs vi

I N D I V I D U A L M A N I F O L D D A T A S U R V E Y

CALEFFI HANDBOOKS SOFTWARE

HEAT EMITTERS BRANCH DATA SURVEY

N Room Q La Heat Emitter ( code ) ta dt cv cd vi

( )

( )

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J. RIETSCHEL - W. RAISSTraité de chauffage et de ventilationLibrairie Polytechnique Ch. Béranger - Paris et Liège

M. DONINELLI - P. RAFFAGLIOPannelli radianti a pavimentoScantec - Bernareggio (Mi)

PIERRE FRIDMANNLe calcul des planchers chauffant a eau chaudeLes editions parisiennes

A. MISSENARDLe chauffage et le refraichement par rayonnementEditions Eyrolles (Paris)

F. KREYTHPrincipi di trasmissione del caloreLiguori Editore

J. J. BARTONElectric floor warmingGeorges Newnes (London)

AUTORI VARIIl riscaldamento a pannelli radianti con serpentine in acciaioBollettino n. 26 Dalmine

B I B L I O G R A P H Y

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DISTRIBUTION NETWORKSMario Doninelli

DESIGN PRINCIPLES OF HYDRONIC HEATING SYSTEMSMario Doninelli

SYSTEMS WITH MANIFOLDSMario Doninelli

SYSTEMS WITH RADIANT PANELSMario Doninelli

T H E C A L E F F I H A N D B O O K S

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MARIO DONINELLI WITH RADIANT PANELS SYSTEMS · buildings, thus achieving the first central-heating type system. However, it was not until the start of this century that underfloor