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Professor Bjarne W. Olesen, PhD Director

International Centre for Indoor Environment and Energy Department of Civil Engineering Technical University of Denmark

Possibilities and limitations for using water based radiant heating and cooling systems.

International Centre for Indoor Environment and Energy

The 20-20-20 EU policy by 2020

Greenhouse gas levels

Energy consumption

Renewables in energy mix

-20% -20% 100%

20%

8,5%

Comprehensive set of legislation to enhance energy efficiency

l

. Directive for the taxation of energy products and electricity

Revision in 2008 . Energy end-use efficiency and energy services Directive Services

. Directive on the promotion of cogeneration Generation Buildings . Energy performance of buildings Directive (EPBD)

. Directive establishing a framework for the setting of eco-design requirements for energy-using products (implementing directives for e.g. boilers, refrigerators, freezers and ballasts for fluorescent lighting

Eco-Design

. Directives for labelling of e.g. electric ovens, air-conditioners, refrigerators and other domestic appliances . Regulation of Energy Star labelling for office equipment Product Labelling

Taxation 3/14

Energy Performance of Buildings Directive – EPBD (2002/91/EC) l

Requirements - for Member States to specify and implement:

§  An integrated methodology to rate the energy performance of

buildings

§  Minimum energy performance standards for new and for

existing buildings that undergo major renovation

§  Energy performance certificates for buildings

§  Regular inspections of boilers and

air-conditioning systems

4/14

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EPBD – Energy Performance Certificate lExample for Member States’ room for manoeuvre:

5/14

Achieving Excellence in Indoor Environmental Quality

•  Physical factors –  Thermal Comfort –  Air quality (ventilation) –  Noise-Acoustic –  Illumination

•  Personal factors –  Activity –  Clothing –  Adaptation –  Expectation –  Exposure time

Energy Efficient Technologies

•  Indoor air quality –  Pollution sources –  Air distribution (contaminant removal) effectiveness –  Personal ventilation –  Air cleaning

•  Thermal comfort –  Low Temperature Heating- and High Temperature Cooling Systems –  Thermo-Active-Building-Systems (TABS) –  Drifting temperatures

 No cooling – decreased performance  Low energy costs  Low operation costs

 Full Air-Conditioning  Constant temperature  Draught, Noise, SBS  High energy costs  High operation costs

 Thermo-Active-Building-Systems  Temperature ramps  Reasonable energy costs  Low operation costs

COMFORT-PERFORMANCE

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CONCEPTS OF RADIANT HEATING AND COOLING SYSTEMS

•  Heating - cooling panels •  Surface systems •  Embedded systems

HISTORY Frank Lloyd Wright's Usonian Houses 1930’s

A lightweight floor slab was used and the traditional basement was dispensed with. By using steam or hot water piping, it became possible to heat the floor, therefore eliminating the need for radiators. The overall result was heat without a draft or temperature variation of the most comfort - cool head and warm feet.

c. 10,000 B.C., China, the word “kang,” can be traced back to the 11th century B.C. and originally meant, “to dry” before it became known as a heated bed. c. 5,000 B.C., evidence of baked floors are found foreshadowing early forms of “kang” and “dikang” (heated floor) later “ondol” (warm stone) in China and Korea, respectively.

c. 10,000 B.C., China

HISTORY

Hypocausts were used from the third century B.C. in ancient Europe.

c. 1904, Liverpool Cathedral heated with system based on the hypocaust principles.

Suspended cooled ceilings

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Radiant surface heating!and cooling systems!

Floor! Wall!

Thermo Active Building Systems!

Ceiling!

The image cannot be displayed. Your computer may not have Reinforcement!

Floor!

Concrete! Pipes!

Room!

Room!

Window!

Embedded piping systems

•  Free use of space •  No cleaning •  Safety •  Comfort •  Energy

6/24/11 Bjarne W. Olesen, ICIEE-DTU 15

Low-Temperature heating High-Temperature Cooling

•  Higher efficiency of boilers and chillers •  Lower distribution losses •  Better use of renewable energy sources •  Low energy consumption for circulation •  Future flexibility •  Low Exergy

THERMAL COMFORT

•  -0,5 < PMV < +0,5 ; PPD < 10 %

•  Spaces with sedentary work : –  Summer clothing 0,5 clo – Winter clothing 1,0 clo – Activity level 1,2 met

•  OPERATIVE TEMPERATURE •  WINTER 20 °C (68F)< to < 24 °C(75.2F) •  SUMMER 23 °C (73.4F) < to < 26 °C (78.8F).

Seite 5 5

OPERATIVE TEMPERATURE

–  to = (hcta + hrtr)/(hc + hr) –  to = 0.5ta + 0.5tr ( low air velocity)

»  ta = Air temperature »  tr = Mean radiant temperature »  hc = Convective heat exchange coefficient »  hr = Radiative heat exchange coefficient

Mean Radiant Temperature

•  tr = ΣFp-i tsi –  Fp-i = Angle factor from person to surface i –  tsi = Surface temperature of surface i –  ΣFp-i = 1

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Angle factor

00,050,10,150,20,250,30,350,40,45

Gulv Loft Vindue Brystning Bagväg SidevägFloor Ceiling Window Out. Wall Back Wall Side Wall

SURFACE HEATING AND COOLING Heat transfer coefficient

8,08,0

6,0

11,011,0

7,0

5,56,5

7,5

8,5

9,5

10,5

11,5

Floor

Ceiling

Wall

W/m2K

Heating Cooling

6/24/11 23

SURFACE HEATING AND COOLING Max. - Min. Surface temperature

40

17

27

17

35

20

29

20

15

20

25

30

35

40

45

Floor

Ceiling Wall

oC

Heating Cooling

Perimeter

6/24/11 24

MAXIMUM HEATING AND COOLING CAPACITY

160

72

42

99

165

42

99

42

020406080100120140160180200

Floor

Ceiling Wall

Heating Cooling

Perimeter

W/m2

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ISO/TC 205/WG 8 Radiant Heating & Cooling System

ISO/DIS 11855-1 ISO/DIS 11855-2 ISO/DIS 11855-3 (July) ISO/DIS 11855-4 ISO/CD 11855-5 ISO/CD 11855-6 (July)

1. Screed 2. Pipes 3. Plastic foil 4. Insulation 5. Levelling 6. Concrete

ALUMINUM HC device: Floor Heating & Cooling (type B), R=0.01~0.1, T=150 & 300

0

20

40

60

80

100

120

140

160

-15 -10 -5 0 5 10 15 20 25 30Heating/cooling medium differential temperature ΔθH=θH-θi [°C]

Hea

t exc

hang

e [W

/m2]

T=150, R=0.01T=150, R=0.1T=300, R=0.01T=300, R=0.1

Figure 4.17 Heat exchange between the surface (with ceramic tiles, wooden

parquets or carpet R?B=0.1 and no covering R?B=0) and the space when aluminium heat conductive device used

Heating/ cooling capacity, EN1264 and EN 15377

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Wood constructions

6/24/11 30

Finite Element Method

Radiant Floor Cooling

Radiant Floor Cooling

OPERA HOUSE

SHOPPING CENTER MUSEUM

AIRPORT

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Slide 33

Opera House in Copenhagen Cooling

•  2,5 MW cooling capacity •  2 systems – 10/15°C and 15/18 °C •  Free cooling from sea water •  Combined radiant floor heating + radiant

floor cooling •  18 km underfloor cooling tubing •  Quiet cooling walls •  De-humidification Condensing coils for

ventilation

BBI airport, Berlin, Germany. 76,750 m² to be heated/cooled with floor system

•  The in-city airports in Berlin will be closed and replaced by the new BBI

•  In future, up to 6,500 persons will be starting or landing at the new airport in a typical hour.

•  There will be a floor heating/cooling realized in 2010

Airport Bangkok HEAT LOADS

•  Once the heat load to the space had been determined, the conditioning system was being developed.

•  The loads for the concourse were 97 W/m2 •  The conditioning systems to remove this heat from the

space was divided as follows: – Radiant Floor 80 W/m2 – Ventilation Air 17 W/m2

Seite 10 10

Airport Bangkok Airport Bangkok

VENTILATION

•  The outdoor air AHU will supply variable outdoor air quantities at a constant temperature to the zone AHU’s.

•  The volume of outdoor air will be varied depending upon the CO2 levels metered in each zone, down to a fixed minimum position

•  Each zone AHU can supply air at 16 C to the space via the displacement diffusers

Ta = 16 oC Td = 10 oC

TsupplyW = 13 oC

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Airport Bangkok TABS Thermo Active Building Systems

Insulation!Floor!

Concrete!

Reinforcement!

Pipe!

Room!

Room!

Window!

Concept of Thermo Active Building Systems

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The analysed building

West room

Width of the room: 3.6 m

Window portion of the outside wall: 50%

Office building

Slab used in simulation Convegno Internazionale AICARR

Prof. Bjarne W. Olesen, International Centre for Indoor Environment and Energy, DTU

Sun protection

Sun protection: Only during occupation and direct exposure of sunlight and operative temperature above 23 °C, reduction factor 0.5

®VENTILATION RATES

During time of occupancy: 1.5 ach

Outside time of occupancy:1.5 ach

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CONTROL OF WATERTEMPERATURE •  Supply water temperature is a function of outside

temperature according to the equation:

•  Average water temperature is a function of outside

temperature according to:

•  Average water temperature is constant and equal to: 22°C in summer and 25°C in winter.

•  Supply water temperature is a function of outside temperature according to the equation:

( ) )22(*6,12020*52,0sup −−+−= oexternalply ttt °C (case 801)

( ) )22(*6,12020*52,0 −−+−= oexternalaverage ttt °C (case 901)

( ) 1818*35,0sup +−= externalply tt °C summer (case 1401) ( ) 1818*45,0sup +−= externalply tt °C winter (case 1401)

PERFORMANCE EVALUATION

•  Range of operative temperature •  Pump running time •  Energy consumption

Operative temperature range, May to September Different control concepts for water temperature, Time of operation 18:00 - 6:00 Uhr

33

14

54 54 52

38

0

10

20

30

40

50

60

70

80

90

100

Tsup =Tdp

Pump Tsup =F(ext)

Pump Tavg =F(ext)

Pump Tavg =22 °C

Pump Tavg =20 °C

Pump Tavg =18 °C

Pump

Control of water temperature

Ope

rativ

e te

mpe

ratu

re ra

nge

[%]

>27

26-27

25-26

22-25

20-22

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Comparison with the norm DIN 1946-part 2

19

20

21

22

23

24

25

26

27

28

-12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32

Outdoor Temperature [°C]

Indo

or O

pera

tive

Tem

pera

ture

[°C

]

Venezia fall16

Comparison with the norm DIN 1946-part 2

19

20

21

22

23

24

25

26

27

28

-12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32

Outdoor Temperature [°C]

Indo

or O

pera

tive

Tem

pera

ture

[°C]

Venezia fall17

Circulation pump on at 18:00 Sunday

Circulation pump on 10:00 Sunday

CONTROL OF WATER TEMPERATURE SUMMER

Operative temperature May to September

Water temperature control. Time of operation 6 pm to 6 am

26 36

26 30 33 39

32 34

0 10 20 30 40 50 60 70 80 90

100

Tsup= f(Ti,Te) Tave= f(Ti,Te) Tave=

22 °C Tsup= f(Te) Tsup= f(Ti,Te) Tave=

f(Ti,Te) Tave= 22 °C Tsup= f(Te) Control methods

Ran

ge o

f ope

rativ

e te

mpe

ratu

re %

>27 26-27 25-26 22-25 20-22

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ART MUSEUM IN BREGENZ

•  Design requirements – Air temperature variations during a day within 4 K – Relative humidity variations less than 6 % during a day. –  Seasonal variations between 48 and 58 % – Room temperature in winter 18 oC to 22 oC – Room temperature in summer 22 oC to 26 oC, occasional up to 28 oC

•  Design load 250 persons pr. day, 2 hours •  Displacement ventilation < 0,2 h-1 •  Floor area 2.800 m² , 4 floors •  28.000 m plastic pipes embedded in walls and floor slabs

ART MUSEUM BREGENZ

•  3.750 m² floor area •  4.725 m² embedded pipes

•  Condensing boiler

•  Ventilation 750 m3/h per floor (first design was 25.000 m3/h

ART MUSEUM IN BREGENZ ART MUSEUM BREGENZ

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ART MUSEUM BREGENZ

Offices M+W Zander Stuttgart, Germany -  TABS –

- in 6.500 m2

MW-Zander Measurements during normal operation

Operative temperature sensor

Air temperature sensor

Transmitters

Seite 17 17

Stuttgart

Stuttgart 24.07. - 28.07, 2000

20

21

22

23

24

25

26

24. J

ul

24. J

ul

25. J

ul

25. J

ul

26. J

ul

26. J

ul

27. J

ul

27. J

ul

28. J

ul

28. J

ul

29. J

ul

Zeit

Tem

pera

tur [

°C]

O1-Operative Büro 4. Stock Fenster-Ost F1-Fläche 4. Stock RucklaufO-Operative Büro 5. Stock Fenster-West O6-Operative Büro 5. Stock Fenster-Ost

Energy concept in BOB.1 Temperatures for one year in BOB.1

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cooling period in BOB.1 Heating period in BOB.1

0

5000

10000

15000

20000

25000

30000

35000

Heizung Kühlung Lüftung Beleuchtung Pumpen Warmwasser Summe

Yea

rly e

nerg

ie c

osts

[€/m²a

]

BestandBOB.1

Energy efficiency

94 % energy saving compared with conventional cooling

60 % energy saving for lighting by daylight steering

The need of energy for heating, cooling, air-ventilation lighting and warm water is 27,8 kWh/m² per year

Energy costs per m², per year: 2,7 EUR, per month 22,5 Cent

Heat pump

Free Cooling and line up to a reversible Heat Pump, A - free cooling by means of ground coupling (cca 10-25 W/m) B - possibel to obtain much higher cooling

capacity by using reversible heat pump

Seite 19 19

Influence of condensing temperature on COP

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

30 40 50 60Temperature, condenser (°C)

COP

Evaporation - 5°C

Absorption Heat Pump

Cooling by using Absorption Heat Pump supported by Solar Heat, 1 - cooling tower, 2 - control system unit, 3 - Solar collector, 4 - buffer tank, 5 - additional heating, 6 –

absorptive heat pump, 7 - floor heating system

Ground Heat Exchanger

a - ground well (hole), b - , c - gap wall,

d - ground collector, e - plate floor cooler, f- soil cooler

BoilerChiller

Temperature-Humidity

Outsidetemperature

Floor temp.

Supply Limiter

ReturnMixing valve

Shut off valves

Control

Room sensor Control unit

Valve

Manifold

Pump

Control of a combined floor heating-cooling system

with individual room control

Seite 20 20

SELF CONTROL

80W/m?

40W/m?

20W/m?

10W/m?

Heat load

FloortemperatureHeat. level temp. tiles

Heat. level temp. carpet

38,4

29,4

24,922,5

31,9

26,2

23,321,7

27,3

23,922,1

21,12022242628303234363840

C°

Floortemperature at 20 °C RoomtemperaturedegC F18 64,419 66,220 6821 69,822 71,623 73,424 75,225 7726 78,827 80,628 82,429 84,230 86

PRE- FABRICATION

Low Exergy Hydronic Radiant Heating and Cooling Why?

•  Water based systems

•  Low temperature heating - High temperature cooling •  More economical to move heat by water:

– Greater heat capacity than air – Much smaller diameter pipes than air-ducts –  Electrical consumption for circulation pump is lower than for fans

•  Lower noise level •  Less risk for draught •  Lower building height •  Higher efficiency of energy plant •  But

–  Reduced capacity? –  Acoustic? –  Latent load?

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International Centre for Indoor Environment And Energy

THANK YOU