Ground Up Magazine - Issue 2 Website

EGSHPAEuropean Ground SourceHeat Pump Association

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Cowboys need not apply why training matters, top hints and tips,

plus the skills required

Blow your mind - top system installations

Get connected - find a pro inside

Green building - renewable energy working together

Lets go loopy - open loop systems explained


2 Ground Up l October 2011


Welcome to issue two of Ground Up magazine. We have some great articles this

month, including an interesting piece on making sure you price systems correctly and

avoid common pitfalls when carrying out site evaluations and quotes and a great story

outlining the importance of training.

Due to the success of the magazine it will become subscription only with effect from

the next issue as we cannot keep up with demand. The good news is we have

extended the “Find a Pro” offer on page 11, which means you can list your business

in our professional directory, become a member of EGSHPA and subscribe to the

Ground Up magazine for only 49.95 Euros.

So enjoy the second issue of Ground Up magazine and remember to email us

[email protected] if you have any submissions you would like to see featured

in the next issue.

InsideMaking the Case How to achieve the best, effi cient and affordable systems for clients

Numerical modelsHow hydrogeolgists and numerical models can assist design

Natural Born DrillerMaking sure the drilling process is correct

Ground Source Energy SystemsA look at a ground source energy system in the heart of London

TrainingMake sure you get it right, look at the best practice and standards

Heating Large areasHeating an area the size of over 100 football pitches

GadgetsWhats the best personal assistant on site

Retrofi tA glimpse into a retrofi t project

European Ground Source Heat Pump AssociationArgyle HouseDee RoadRichmondSurreyTW9 2JN

Not for Profit Company Limited by Guarantee, Registered in England & Wales, Company No. 7689830

Homepage: www.egshpa.com

Contact Us: [email protected]

The Team

Adrian BridgwaterHead of Social Media & [email protected]

Paul KilbyEditor

Dale HoldbackTechnical and Industry [email protected]

Richard LaytonHead of [email protected]

Nathan BerkleyHead of Media and [email protected]

We would also like to thank the following companies who supplied fantastic content for this issue: • Don MacIntyre from Geothermal

Industries Ltd• Antonio Gennarini from ESI Ltd• Chris Davidson from Geothermal

International Ltd• Hoare Lea• Olof Andersson from SWECO

Environment AB• Martin Chandler of The Clean

Footprint• Transition Bath

DisclaimerGround Up is a trademark and may not be used or reproduced without the prior written consent of EGSHPA. Ground Up is published in the UK by EHGSPA and is sold subject to the following terms: namely that it shall not without the written consent of the Publishers be lent, resold, hired out or otherwise disposed of by way of Trade at more than the recommended selling price shown on the cover and that it shall not be lent, resold or hired out in a mutilated condition or in any unauthorised cover by way of Trade of affixed to or as part of any publication or advertising literary or pictorial matter whatsoever.

Welcome

3October 2011 l Ground Up



Making the CaseIts been my observation that before any marketplace will

fully embrace GSHP all stakeholders must be genuinely

convinced of its benefi ts. I see it as a sort of rule. I call

it: Marketing Rule #1. Oh I know there’s been lots of

rhetoric about being Green, Clean, and Sustainable, and

the thought of saving planet earth makes people all warm

and fuzzy on the inside, but at the end of the day someone

has to justify paying the bill for these systems which many

times are much more expensive than conventional HVAC.

Its an uphill struggle and very expensive to persist in

pushing a new technology forward but someone has to do

it or it goes nowhere. Many times this is why governments

step in to better their nation, or sooth their national

conscience, by boosting the incentives to adopt green

technologies either through tax credits, low interest loans,

or outright grants. However, with or without governments

artifi cially propping up our industry there is much that you

and I can do to help the market pragmatically embrace

our ground source systems without the emotional fuzzies

blurring the economic realities. So I want to focus in on just

a few points regarding the economics of GSHP that might

help others who are pushing this technology forward. Why

economics? Because at the end of the day its money that

really matters.

There are two sets of economics that drive GSHP technology in the marketplace.

First we have the Macro or National Economics, that are only ever considered by those responsible for the bigger picture: Government, Utilities, very large Industrialists and Developers who look at the economic impact this technology is going to have on a regional or national scale.

Second we have the Micro or System Economics. The economic impact this technology is going to have on its owner. It is the personal cost/benefi t of owning this system. Its this level of economics that we want to explore today since it is this level that concerns our potential Clients.

In any mechanical system we have four costs that determine the amount of money someone will have to pay over the life of this entire system. In calculating these costs we look to fi nd ways to save within all of them as compared to a conventional system. When someone talks only about energy savings they are unfortunately painting a very incomplete and inaccurate picture for the consumer and many professionals even fall into that trap.

Whenever you are preparing to “Make the Case” for any Alternative Energy Technology, including GSHP systems we must do our homework. Compile the best data we can to make our case. “Best” data means relevant, and current. Be honest and fully inform our client about what he can expect to pay for this system over its lifetime and what he can expect to save over its lifetime, even if his ownership is only for a part of that lifespan. We do not need skewed proposals to make the case. GSHP technology has proven itself in every climate and geology in the world. It works, and works well.

There are fi ve elements that go into the Economics of GSHP technology at the system level, the Micro Economic level. They are:

1. Installed - “First” Cost

2. Operating Energy - Cost

3. Maintenance & Repairs - Cost



4. Life Cycle Replacement - Cost

5. Savings - Benefi t

I like to impact the Micro Economics right at the conceptual stage of the project. This is truly the only place to begin, right when we are brainstorming about what kind of GSHP system this project needs. I try to follow two guiding principles to arrive at the best system Coeffi cient of Performance (COP) possible.

1. Simple Designs – small water to air heat pumps, with their own small circulation pumps located directly in the zone they serve rather than large heavy centralized plants with multizoning and great complicated distribution systems running all over the building. These large systems need heavy strong roof beams to support the central plant on the roof, or large mechanical rooms, and lots of ceiling space to run miles of duct work. I try to keep earth exchangers in 8 to 20 ton groupings designed to purge and fl ush easily and require as little pumping power as possible.

2. Individual Controls – also simple. Most often a staged heat/cool thermostat tied directly to the little heat pump serving that zone.

There is more to a GSHP system than just a heat pump and while heat pump effi ciency is important it is only one component determining the system effi ciency. We need to move circulation fl uid on both the source side and the load side. We also need to move air. We may even have a separate HRV air to air exchanger in the ventilation system, we will likely also have exhaust fans. This may be a hybrid system coupled to a water tower or other parallel system. All of these energy demands must be added to the heat pump energy demands to get the total price tag for running this system. All of these smaller systems make up the total GSHP system and they all consume electricity. Each of these components has an effi ciency, a COP. They will each impact the other and at the end of our calculation we can estimate the System COP. It is this System COP that matters most because this determines the total electrical bill the end user pays. And don’t forget we need to control this whole system.

I have seen the proposals from controls companies. Their control packages are nothing short of magical, but they really

only excite the techy-nerdy side of us. And some of these systems consume far more energy than they are worth.

A word about maintenance costs and life cycle costs. If you really want to impact your Client, do a fair estimation of these two elements. Over the life of an average GSHP system using ASHRAE research fi gures the savings are so substantial they can be as large as the energy savings in some buildings. Its little wonder that we are seeing ESCO companies in North America lining up to sell geothermal systems using BOT and Utility fi nancing models even for private home owners. They are making very big profi ts and still saving homeowners energy dollars too.

A fi nal note. To achieve the best, honest, effi cient and affordable systems for our Clients, we have to keep one over-arching pragmatic question hovering over our heads all the time at each stage of our design right from concept to delivery. Do we really need this level of sophistication?

I wish you the very best as you move forward.

The author, Don MacIntyre is a Certifi ed GeoExchange Designer from Canada registered with the Association of Energy Engineers, a trainer with the International Ground Source Heat Pump Association, and CTO with Tel Aviv startup Geothermal Industries Ltd. Contact [email protected].

Understanding how numerical models and hydrogeologists can assist the design of Ground Source Energy schemes

Architects and building service engineers regularly develop large complex building models to assess the energy requirements and performance of buildings. These models are based on a

set of input parameters, such as building fabrics, building occupancy and local weather conditions amongst others. The models help inform the size and number of ground heat exchanger(s) needed in a ground source energy (GSE) scheme to provide the building loads. Ground heat exchanger(s) can be one or more borehole doublets used for groundwater abstraction/injection in open loop systems, or an array of Borehole Heat Exchangers (BHEs) for closed loop systems.

The use of models that actively simulate the performance of the ground heat exchanger is less common, although these can provide a range of benefi ts to the overall design of GSE schemes. The degree of complexity is generally proportional to the scale of the proposed scheme. Smaller schemes benefi t from simple tools that are based on simplifi ed underlying conceptual models, while larger and more complex schemes benefi t from numerical models that can account for more complex ground and/or operational conditions.

The effects of groundwater fl ow across a BHE in closed loop systems are typically not assessed by the more common analytical software tools used by the industry. The effects of groundwater fl ow will vary: BHEs that operate with heat extraction or injection only are typically more sustainable in the presence of groundwater fl ow; groundwater fl ow may not benefi t schemes that operate in balanced mode (both heating and cooling). The potential for thermal short-circuiting (the feedback of injected groundwater temperatures via abstracted groundwater) in open loop schemes is not always assessed. There is mounting evidence, even in a young market like the UK, that schemes are failing because of rising groundwater temperatures at the abstraction borehole due to inadequate design.

Closed loop schemesUnderstanding the performance and sustainability of the ground loop array is important in the design of any GSE scheme. Numerical models such as FEFLOW can account for the detailed layout of the borehole array rather than being restricted to a range of standard borehole array layouts, typical of the more common software tools. They are particularly valuable where greater confi dence in the performance of the proposed layout of the ground loop is required. FEFLOW models can explicitly represent the geological layering beneath the site and differing geothermal properties along the BHE.

Detailed distribution of properties within the borehole array allows all interference effects to be calculated specifi cally for the proposed design. FEFLOW can also represent the effect of groundwater fl ow past the borehole array. Accounting for the transfer of energy due to the effects of groundwater movement past the BHEs allows less conservative designs and will lead to signifi cant cost savings , especially initial drilling costs.

For larger closed loop GSE projects, the area required for the ground array of boreholes is often a key constraint, Balanced schemes, where the heating and cooling loads are comparable, allow signifi cantly larger energy loads to be sourced from a more limited area than would be the case for unbalanced schemes. Figure 1 illustrates the impact of using tight borehole confi gurations where energy loads are signifi cantly unbalanced. The geological setting is typical of North London where boreholes penetrate through London Clay and the Lambeth Group into the Chalk.

Figure 1 shows how unbalanced seasonal heating and cooling results in a small net ground cooling spreading beyond the boundaries of the array. Note that in this instance, a large energy load is being supplied from a rather small site footprint, and the success of the scheme would require a more balanced seasonal heating and cooling load. The BHEs of this array will behave differently over the lifetime of the scheme. Boreholes located at the centre of the array will decline in heating effi ciency when compared to the boreholes around the margins. Quantifying scheme performance allows alternative, sustainable and more optimal borehole confi gurations to be investigated.

Figure 1 A rectangular layout of 58 boreholes for a large energetically unbalanced development in central London. The boreholes have an inter-axial distance of 8 m. The fi gure is a snapshot of a FEFLOW model that shows how long term (25 year) operation produces a cooling of the boreholes located in the centre of the array.



Numerical models like those developed with FEFLOW are particularly cost effective for larger schemes, or for those installed in more complex settings, where conventional tools require a conservative and less effi cient solution to be used in order to have confi dence in the long term. Visualisation of the results with three-dimensional time series movies assists with communicating the results to wider audience. On large schemes, the savings that can be achieved on drilling will often out-weight the costs for developing the ground models. In addition, there will be added confi dence in the performance of the scheme.

Open loop schemesOpen loop schemes typically involve different challenges during the design process and are more strictly regulated in the UK and abroad. The feasibility of such schemes depends upon obtaining adequate groundwater yields to supply the heating or cooling energy demand of the building. These perceived risk and regulatory delays have often caused designers to favour closed loop designs to open loop schemes, even in areas where groundwater yields are notoriously good and where the economics of the development indicate that an open loop scheme would be preferable. These decisions have sometimes been made because project managers are not aware of the benefi ts of having suitably qualifi ed and experienced hydrogeologists in the design team right at the start of the project, which will lead to the success of open loop schemes if the site conditions are right. Hydrogeologists have the knowledge, the skills and the experience to assess groundwater resources and reduce the risks associated with the uncertainties on groundwater yields and aquifer properties.

The hydrogeologist will initially undertake a geological and hydrogeological feasibility assessment. Preliminary numerical models can be developed as part of this work to establish the potential for thermal breakthrough. Schemes that are proposed for particularly complex settings (e.g. densely populated urban settings like central London), where there is a risk of causing derogation to nearby groundwater users, or where the properties of the underlying aquifer are such that there is a risk of thermal breakthrough, will require more complex models. Detailed numerical models can provide greater fl exibility in representing and assessing the feasibility of the proposed medium to large GSE schemes when compared to simpler tools.

Figure 2 shows a vertical slice through a large numerical heat transport model built for London Underground as part of the Cooling the Tube programme to provide a renewable energy cooling solution for the Tube stations.

The purpose of the models was to simulate the effects that the proposed ground source energy schemes might have on groundwater temperatures in the wider environment and to identify potential

interference between neighbouring schemes. The heat plumes in Figure 2 shows how heated groundwater discharged at 20 l/s to the Chalk aquifer affects nearby abstraction boreholes. The snapshot is taken for a 50 year simulation. At this stage, the groundwater abstracted from impacted boreholes will be slightly warmer than the aquifer background temperature. Consequently, the cooling effi ciency of the heat pumps will decrease and running costs will increase in the form of higher electricity consumption.

These model results have been used to inform the design process and the identifi cation of those stations where GSE is most appropriate. Further development of the models has also been undertaken to develop a groundwater model that can be used by Environment Agency hydrogeologists to assess the individual and cumulative impacts of open loop GSE schemes in central London. A hydrogeological conceptual model of central London is shown in Figure 3.

A signifi cant proportion of heat is transported by advection in the upper 30-40 m of the Chalk aquifer. Experienced drillers and hydrogeologists know that this interval of the Chalk aquifer is generally more productive due to the higher degree of fracturing within the aquifer. However, the higher degree of fracturing within this interval may also be responsible for “short circuiting” between the abstraction and injection boreholes. The risk of short circuiting will increase as the distance between the abstraction and injection borehole decreases. These and other uncertainties can be quantifi ed using modelling in the design of open loop GSE schemes.

In this article we have provided some insights into the need for having a scientifi c, yet pragmatic approach to the design of GSE schemes where adequate models can assist and improve the design process. The selection of the most appropriate model for describing the ground source is a role that generally lies with those professionals that have the right geological and hydrogeological knowledge and skills.

ESI is the UK’s leading independent scientifi c and environmental consultancy specialising in water resource management, land quality and ground source energy. ESI provides a range of GSE services to property agents, architects, building service engineers, installers and drilling contractors.

Further details can be obtained by contacting Antonio Gennarini [email protected]. +44 (0)1743.276100

Figure 2 A vertical section through the model built for central London.

Figure 3 3D model of Central London showing the conceptual understanding of how a heat plume moves within the Chalk aquifer.





Natural Born DrillerAs anyone who’s drilled deeper than a child’s sandpit will tell you, drilling can be an incredibly

complex operation. But as Ground Source Heat Pumps become increasingly popular with

average homeowners - often with little or no knowledge of what drilling entails - what do we as

professionals need to tell them to ensure they’re informed?

Ground Up magazine dug deep, and came up with these suggestions …

The green credentials of ground source heat pumps are

already well known and accepted, but for many considering

them, the fi nancial implications – both the initial investment

and ROI – are equally important. Knowing and being able to

explain what operations need to be undertaken, and why, can go

a long way to reassuring (or perhaps even convincing) clients that

the initial cost is justifi ed, and indeed necessary if the ROI is to

be maximised. Simply telling a client that drilling has undergone

a substantial evolution from the early days and is now a very

specialised and technical activity requiring substantial skill and

professional expertise to achieve the desired result may not be

enough – but what topics should be explained. After lengthy

deliberation we suggest the following needs to be communicated:

• During the planning stage it may be necessary to cover such

issues as how far from buildings the borehole needs to be –

freezing ground temperature induced subsidence can take a big

bite out of ROI.

• Also, explain the need to avoid siting boreholes anywhere near

large trees whose subsequent root growth may damage the

loops.

• Planning permission is of course an obviously necessary step,

but might there be any problems connected to the noise

produced by drilling? Worth mentioning.

• Might the specifi c geology of the site present any possible

problems? Such as sandy soil increasing the probability of

the borehole collapsing, and the add-on costs of installing

temporary steel casing. Many people expect the easiest drilling

to be into soft and loose geologies. However the opposite

is generally true. All sites have varying underlying strata with

differing levels of saturation, rock types and mineral content - all

factors that can affect the thermal conductivity over the length

of the proposed vertical penetration beneath the site into which

the system is to be installed. It therefore follows on that the

design of each system is ‘site specifi c’. Is the client aware of

this?

• How long the drilling will take: We all know a typical domestic project will take 5 - 15 working days. Explaining the steps involved, and why they are necessary, will go a long way to justify costs.

• The need to perform electronic scans of a borehole site to detect any utilities i.e. gas, electricity, water, etc. Perhaps it may be necessary to dig a trial pit to double check for existing utilities.

• The cost and time of transporting specialist drilling equipment to site (not to mention the initial outlay for purchasing the equipment).

• Preparing the site. For example, the setting up of heavy duty matting to protect lawns, removal of ornaments, protection of plants, etc.

• The reasons why it is necessary to do a pressure test on the loop.



• The importance of backfi lling the hole using a good quality, high thermal conductivity grout. Also communicate why this procedure is complicated because there can be no voids in the grout - effi cient heat transfer to the loop is vital for ROI. It should also be mentioned that the grout will go a long way to stabilising the borehole.

• Should the pipes be left for any length of time before connection to the heat pump, explain the importance of adding a good quality biocide solution to the water in the pipes to prevent fungal/bacteriological contamination of the system.

• Clean up of the site. The safe and legal disposal of waste is costly (as are the fi nes for the non-safe and non-legal disposal of waste!).

• Remember to point out that once installed there is no need for regular servicing or yearly safety checks, as with other systems.

We hope this article goes some way to helping professionals provide informed, relevant and complete information to their clients. It is hoped that through better understanding of the processes and costs involved with the installation of GSHPs the benefi ts will be maximised to all involved.The information provided above is for general guidance purposes only and should not be used to determine individual borehole parameters.



Ground SourceEnergy SystemOne New Change is Land Securities’ latest development

located on Cheapside in the heart of the City of London.

It is London’s newest shopping destination, complete with

cafés and restaurants from renowned chefs and fl agship

menswear and womenswear fashion brands, all overlooking

London’s most famous landmark, St Paul’s Cathedral.

HIGHLIGHTS

• Gross area 560,000 ft2.

• Net offi ce 340,000 ft2.

• Nett retail 220,000 ft2.

• Total cost – £540m.

• Area equivalent to 12

football pitches

• One of the largest offi ce

� oor plates in London.

• Highest and largest public

roof terrace in London.

• Largest single basement in

the City

• Largest commercial

Ground Source Energy

System in Europe.

• First retail mall in the City.

• CO2 emissions 50% better

than CIBSE benchmark

building.

• The perimeter of the

building is half a kilometre

long.

• 6500 Glass panels of

which 4500 were unique.

• Building futures: Building

of the Year 2010 at MIPIM.



The BuildingOne New Change is a contemporary building with

a total of eight fl oors comprising offi ces on the top

four fl oors, a public terrace at roof level on the sixth

fl oor, and shops on the Lower Ground, Ground and

First Floor. With around 60 stores spanning the three

fl oors, One New Change is one of the largest shopping

centres in central London, rivalling other London

shopping hot-spots. A panoramic lift in the middle

gives direct access to new and exciting views over St.

Paul’s Cathedral dome.

Sustainability has

been central in the

design of One New

Change, which has

reduced its carbon

footprint by at least

10% through the use

of renewable sources

on site. This equates

to a saving of around

900 tonnes of C02

emissions annually.

The development has

maximised its energy

effi ciency through

the use of large-

scale geothermal

heating technology.

This system means

One New Change

can be heated and

cooled with extreme

ease simply by using

geothermal energy.

Drilling to a depth

of 150 metres,

Land Securities has

installed a ground

source energy

system which is the

largest commercial application of the technology in

Europe. As a result, One New Change has received an

‘excellent’ sustainability rating under BREEAM (Building

Research Establishment Environmental Assessment

Method), which measures the environmental impact of

buildings.

The heat is extracted and rejected using the ground

with energy piles, an open loop well and roof top dry

air coolers.Continued >

THE GROUND SOURCE SYSTEM EMPLOYS THREE MAIN HEAT TRANSFER MECHANISMS:

CLOSED LOOP ENERGY PILES

A closed circuit of pipe work is

embedded deep within the foundations

of the building. Heat Exchange Fluid is

circulated within this network of pipes

turning the entire structural foundation

into a giant heat exchanger.

OPEN LOOP WATER WELLS

Two Water Wells spaced in opposite

corners of the building can extract or

discharge water with

the aquifer beneath the City of London.

Extracted water can either have heat

added to or taken

from it before being discharged back to

the aquifer.

DRY AIR COOLERS

Large fans blowing air across an

array of pipes on the roof enable heat

rejection when the fl uid within the pipes

is warmer than the surrounding air.

Ground Source Heat Pump System Schematic



Continued on page 14 >



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EFFICIENCY & CARBON SAVING

The Ground Source Energy System is designed to provide up to

2.3MW of peak cooling and over 450,000kWh in a year.

In heating mode the peak is up to 2.4MW and the system is

capable of providing over 450,000kWh annually. The system will

save over 10% of CO2 emissions compared to the conventional

alternative.

The entire building performs 52% better than the CIBSE

benchmark building (based on ECON 19) for annual carbon

savings.

The building contains 248 rotary bearing piles with diameters up

top 2400mm, 192 of these contain geothermal loops for heat

exchange in the piles. The pipe work in the piles is connected

together beneath the slab and rises into the plant room.

Two water wells are installed to 131 meters below Ground Level.

The Wells are 355mm diameter, cased with steel through the

London Clay and Thanet Sands into the Chalk Aquifer The Static

Water Level was measured at 47.5m below ground level.

The Aquifer is capable of yielding in excess of 15 litres per

second with a draw-down of 8m Environment Agency Licenses

to Abstract and to Discharge were granted following the

construction and testing of the Wells.

There is a pump in each Well in a duty & standby confi guration.

The high density polyethylene heat exchange loops were installed within the steel reinforcement cages.

The piles were drilled to the required structural depth.

The reinforcement cages complete with ground source loops are lowered into the hole prior to the concrete being poured.

The energy pile loops brought back to the plant room ready for connection



Reference:

Geothermal International Ltd.

Spencer Court

141-143 Albany Road

Coventry

CV5 6ND

United Kingdom

T: +44 (0) 24 7667 3131

[email protected]

www.geothermalint.co.uk

Hoare Lea

Glen House

200-208 Tottenham Court Road

London

W1T 7PL

Tel: 020 7890 2500

[email protected]

www.hoarelea.com



Do you think training is too expensive?Consider the alternative!This article has been submitted by an investor in the geothermal industry, who has a vested

interest in the furtherance of best practice and standards for the energy business as a whole.

I have been following EGSHPA on Twitter since the

organisation fi rst announced its new web presence. I must

say that it is both refreshing and encouraging to know that

an association like this has been formed with a specifi cally

agreed remit to educate geothermal installers and industry

related professionals.

I was involved with a ground source heap pump (GSHP)

installation company some fi ve years ago (although my

background is banking), when a plumber and a builder,

who were contacts of mine, approached me to invest in a

geothermal installation company. At the time I knew very

little about the industry, but after doing a little research it

was clear to see that this was an area with the potential for

rapid expansion and, in some areas perhaps, turn out to be

profi table for the prudent investor with the right approach to

onward management.

Plunging ahead blindly?

I invested a considerable amount of money into this venture;

while my two partners advised me that they were experts and

knew all there was to know. We proceeded to purchase a drill

rig and grouting equipment and then advertised our services

as widely as possible.

Within no time, we had our fi rst customer. My partners turned

up on site on day one with our new drill rig, but as neither

of them had any solid experience in drilling they failed to drill

past 20 meters.

As a result, the “vertical loop confi guration” they had originally

planned was quickly abandoned and so they proceeded to

dig trenches. The heat pumps were installed, in a typical “plug

and play” manner — or, as I later came to realise, it was more

a case of “plug and pray”. Of course, I can now look back

and laugh (albeit in a slightly guilty manner).

Needless to say, the system didn’t work at all — and this was

not the fault of the equipment, it was simply down the fact

that my co-workers did not have the requisite skills or track

record. Worse still, after that initial botched project, the heat

pump manufacturer refused to trade with our company.

A bad workman blames his tools

Still blind to our lack of credentials and skills, we ploughed

on down our non-trained road to calamity. We found another

heat pump manufacturer in France that would supply us,

we installed our fi rst new unit and the compressor burnt out

within the month. We had numerous discussions with the

manufacturer but the blame was constantly put down to the

installation company – um, that was us.

We now had our second heat pump manufacturer that

refused to supply our company. We were beginning to

question our competency - something we should have done

at the outset of course.

At this stage I was becoming concerned that my partners

were incapable of installing these units, and as I was not

from a technical background I could offer little advice,

but I was reassured that the problems were down to the

manufactures.

We now had to fi nd a third heat pump manufacturer to

supply us, which we did. Our next unit was installed for a

communal swimming pool. The initial sizing and planning

was carried out and the heat pump was installed. Within

no time at all the pipes on the ground loop were white with

frost - resembling something from a cryogenics laboratory -



IGNORANCE IS NO EXCUSE

So why did it go so badly wrong? Well, to put it simply, ignorance. Our plumber didn’t realise the complexity of installing a GSHP and had absolutely no idea how to size a ground heat exchanger. GSHPs are the most effi cient systems available, and yet they could get a bad name if companies continue to trade without proper training. That’s why I fully support the EGSHPA and hope this article will encourage individuals to carry out the appropriate training and use tools like this site for guidance and advice.

and the unit would repeatedly freeze. The pool had only gained

a couple of degrees in temperature. A short time thereafter, the

heat pump packed up all together and we were left battling with

our third heat pump supplier.

Same (installation) shift, different day!

Our company then carried out various domestic installations, all of

which resulted in dissatisfi ed customers and lawsuits. My partners

and I have fallen out over this debacle and the company has since

gone into liquidation.

So what happened and why? I’ve spoken to competent

companies since and having analysed our installations I can

conclude the following:

1. Don’t use a rule of thumb to size a ground loop.

Our company used a magic 80w per meter ground loop. So an

8Kw GSHP would have 80 meters of drilling. This is wrong as

it doesn’t take into account the properties heating and cooling

requirements nor does it reckon with the ground conditions. It’s a

perfect formula for a disaster.

The same rule of thumb was used for all size properties,

irrespective of geographical location. I understand now, that

designing a ground heat exchanger is a complex task and should

only be carried out by trained professionals.

2. Design the loop correctly.

Not with one pipe 32mm dia from the unit, with no headers and

the same diameter pipe for the bore holes. Design headers and

allow for different diameter pipes and calculate fl ow rates.

3. Don’t use cheap off the shelf circulation pumps.

It’s ridiculous to use cheap pumps just because they are in stock.

A circulation pump needs to be selected based on the criteria

of fl ow rate requirements of the heat pump and pressure drop

depending on the size/length of the ground loop.

Calculate the heating and cooling loads, and size the heat pump

accordingly. Don’t use a rule of thumb, i.e. a 100m2 house will

be ok with a 6 to 10kw unit – depending on what we have in

stock. Use suitable software to size the ground loop, and on

larger projects carry out a conductivity test once you have a bore

fi nished.



Heating an area the size of 100 football pitches?But how did they do it?Arlanda Airport has the World’s Largest Energy Storage Unit, saving over 7,000 tonnes of CO2

a year and yet still heating an area the size of 100 football pitches – but how did they do it?

In this article the Aquifer Thermal Energy Storage (ATES) system is described, as well as the site investigations that were needed to develop this impressive project.

IntroductionThe world’s largest energy storage unit − the aquifer that supplies space cooling and heating for Stockholm-Arlanda Airport − has been in service since the summer of 2009. All cooling of airport buildings, including the terminals, come from the aquifer. Arlanda consumed as much energy as a city of 25,000 people. Areas as large as one hundred football pitches need to be cooled in summer and warmed in winter. During the summer, the aquifer supplies cooling to the airport’s buildings while at the same time storing heat. In the winter, this stored heat is used in the ground heating system at the airport’s aircraft parking stands and to pre-heat ventilation air in the buildings. The aquifer reduced the airport’s annual electricity consumption by 4 GWh (no longer needed for the operation of electrical chillers) and its district heating consumption by around 15 GWh. The system effi ciency is world class. No heat pumps are used and electrical chillers less than 100 hours per year, gives a SPF closer to 100.

Stockholm Arlanda airport is situated close to Stockholmsåsen (the Stockholm esker), an extensive glacial formation formed in the last ice age (see fi gure 1). Eskers often provide excellent conditions for large scale ATES systems, by having high permeability and favourable boundary conditions. At Arlanda, impermeable rock ridges divide the esker into several separate sections. The deepest section forms a natural trough that is remarkably suitable for an ATES application. With eleven high capacity wells (5 cold and 6 warm) and a total maximum fl ow of 720 m3/h, the system can provide the airport with heat and cold at a capacity of at least 10 MW. In terms of thermal energy, up to 20 GWh annually can be produced. The storage temperature on the warm side is expected to be around 20oC while the average temperature on the cold side is some 5oC.

The project, administrated by LFV (the Swedish Civil Aviation Administration), started in early 2006. Since then it developed in several steps with more and more extensive site investigations. In parallel, a far-reaching permit procedure has been carried out, ending with a conditioned permit for realization in early 2008. After that the project was detailed designed and the wells drilled and tested. The system was put into operation in the summer of 2009.

Overview of the SystemThe ATES system consists of two groups of wells, forming a “warm” group in the southern part of the aquifer, and a “cold” group in the northern part. The wells are connected to a pipe system ending at the distribution centre where heat and cold from the ATES system is transferred over to a distribution pipe through a large plate heat exchanger. The geographical system lay-out is shown in fi gure 1 (SWECO 2007).

In the distribution centre (Bef. kylcentral) there are a few remaining chillers that can be used for peak shaving of cold, if required. The system is also connected to the lake Halmsjön and this may be used for the dumping of surplus heat from the warm side of the aquifer and for surplus storage of cold in the winter. The lake was previously used for the dumping of a large amount of condenser heat from the chillers that are now obsolete.

The cold side will be charged with natural cold that is mainly derived from out-door air. This is achieved by distributing heat from the warm side of the aquifer to the ventilation systems and to the gates of the airport. At the gates there are ground heating systems for the purpose of keeping the gates free of snow. Currently district heating is used for this function. It has been shown that most of the energy needed for gate heating can be replaced by ATES heat at a temperature of +20oC (Persson 2007). The return temperature from pre heating of ventilation air and gate warming will be in the range of 3-5oC.

In the summer the fl ow of the ATES system will be reversed and the



stored cold will be utilized for air conditioning. The return temperature to the warm side will in most cases be in the order of 15-20oC. However, by using the ground heating systems at the gates as solar collectors, the temperature can be increased to a maximum of approx. 30oC. On average it is expected to have a storing temperature of approx. 20oC.

As shown in fi gure 1, there are fi ve cold wells and six warm wells connected to the main distribution system. The mains and the connecting pipes are made of plastic (PE) and are not insulated. They are placed at a frost safe depth of approx. 1.5 m. The dimension of the main pipes is 350-450 mm and the well connection pipes 150-250 mm. The total piping length is approx. 2,700 m.

The wells are screened and of the type “lost fi lter completion”. These types of wells are developed by air lifting, or hydro-jetting, in order to wash out fi nes and accumulate coarse particles around the wells screen (natural development), see fi gure 2 (SWECO 2007).

Depending on the local hydro-geological condition the well depth varies between 15-30 m. For the same reason the capacity also varies (30-60 l/s) and so does the dimensions (270-400 mm).

The wells are equipped with submersible pumps and with doublets of re-infi ltration pipes. To regulate the production fl ow, the well pumps are all frequency controlled. For controlling and monitoring reasons, the wells are equipped with temperature and pressure sensors. Back valves in the riser pipe and regulating valves in the return pipes keep the water under hydraulic pressure at all times. Together with air tight well caps, this solution minimizes problems with clogging and corrosion.

Aquifer Shape and GeometryOriginally, the esker formed a 100-200 m wide ridge with relatively steep slopes. However, today this form only remains for a short distance east of the lake. At other places the esker was levelled during the construction of the airport.

In the project 38 slim steel pipes were driven down to the bedrock for sampling and spot hydraulic mapping. Also included in the site investigations was a radar survey in order to map ground protruding bedrock bodies. An essential part of the site investigations were two long term interference pumping tests for the estimation of the aquifer hydraulic properties and boundary conditions, and for chemical analyses of the water. All gathered data was later used for technical design and for the permit application.

As can be seen from the long section, fi gure 3, the esker is cut by ribs of the underlying bedrock. These ribs are tight and separate the esker into several hydraulic systems, of which the lowest is used for the ATES plant. This hydraulic system is partly controlled by the lake Halmsjön - it has a slight hydraulic contact with the esker. Elsewhere the esker is drained to the east, marked by a wet land area with organic soils at the side of the esker. A high level of the bedrock in the middle of the esker was used to form a natural boundary between the warm and cold side of the aquifer.

It was also established that the bedrock surface below the esker is eroded and forms a minor cigar-shaped depression beneath the esker, clearly shown on the cross sections in fi gure 4. This was useful for the project since the



bedrock seems to be practically water tight. Also, the slopes of the esker are often dressed with fi ne-grained sediments (silt and clay) or occasionally with peat deposits. This prevents larger leakages when the ground water level is increased (at reinjection), and also decreases the environmental impact on the surroundings.

By using several conceptual cross sections, the volume available for storage was estimated to be 3.2 million m3. From this theoretical gross volume it was estimated that approx. 2 million will be thermally active with temperatures that are feasible for heating and cooling. However, by overloading this volume may be increased to some extent.

Aquifer PropertiesThe ground water level in the esker is practically fl at and matches the level in the lake. That level is controlled at the lake out-let and stays almost the same year round. Hence no natural fl ow disturbing the storage function is possible.In the north the groundwater level is approx. 7-8 m below the surface, while in the south, it is a little higher, around 4-5 m. This higher level in the south is a limiting factor for the uplift of the groundwater level during infi ltration. For this reason there are six wells in the south in order to spread the infi ltration points over a larger area.

Mainly based on the evaluation of pumping tests the hydraulic properties of the aquifer were estimated, see table 1.

In the northern part, the fi ne grained sediments towards east has a estimated k-value in the order of 5×10-4 m/s, while the boundary towards the lake in west is estimated to be ten times lower. In rest of the esker the k-values of the side sediments were estimated to 2 x10-5 m/s. These k-values indicated that the esker boundaries will only marginally disturb the storage function.

During the pumping tests the temperature of extracted groundwater was continuously measured and found to be practically constant at 8oC.

The heat capacity of an esker is strongly related to its porosity. The porosity was not a subject for analyses, but by experience a value of 30 % was used, indicating a heat capacity in the order of 0.8 kWh/m3 x oC.

The thermal conductivity of the esker, especially the overlaying dry sand and gravel, will mainly affect the energy losses from the storage. The values used in the project were 0.5 W/m x oC for dry sand and 1.5 for the wet fi ne grained sediments at the sides of the esker.

Water chemistry is directly related to the different kinds of potential corrosion and clogging problems that may disturb the operation of an ATES plant (Andersson 1992).

During the pumping tests several samples were taken and analyzed. The results showed sweet water that is slightly oxidized uniformly distributed all over the area. The oxidized environment was mainly indicated by the low content of dissolved iron and manganese and that nitrogen was in the form of nitrate. However, there is a signifi cant difference between north and south concerning the content of dissolved carbonates. In the north the hardness is 16 odH. In the south this fi gure is 24, caused by a higher content of magnesia. Also the content of sulphate is much higher in the south, 150 mg/l, compared to 30 in the north. The content of organic material is low, but showed slightly increased values with time during both the pumping tests.



Based on the chemical and physical status of the water no severe problems with corrosion, clogging by iron or manganese precipitates, or scaling were expected.

Simulation of the operationIn order to study the draw down and up-lift in the aquifer and its surroundings the operation was simulated by a 3D hydraulic model (MODFLOW). The simulations were carried out for the maximum fl ow rates in both directions (the summer and winter modes).

The summer situation was at a fl ow of 270 m3/h (200 l/s), illustrated in fi gure 5. At this mode the maximum draw down around the cold wells will be approx. 2.5 m, while the up-lift cone around the warm wells would be practically the same. The simulations are done till stationary conditions have been reached in the aquifer.

The simulation for the winter mode with pumping from the warm wells and injection in the cold wells showed that the draw down around the warm wells will be in the order of 3.5 m, while the uplift cone around the cold wells corresponds to the draw down at discharge. The difference between draw down and uplift values in the south refl ects the narrow trough shape of the esker here.

The draw down and uplift cones follow the elongated boundaries of the aquifer and it was clearly shown that both the sides and the rock ridges act as negative hydraulic boundaries that limit the infl uenced area substantially. It was also shown that Lake Halmsjön has a limited infl uence on the hydraulics, probably due to fi ne grained sediments at the bottom of the lake.

ConclusionThe Arlanda ATES project was developed in several steps over a long period of time. The main reason for this procedure is the duel handling of technical and permit related issues. This procedure is necessary for any large scale Swedish ATES project. The duration may vary, but normally it takes approx. 2 years from starting a project to having it brought on line.

In order to have a complete technical design a thorough environmental assessment analyses was needed in the Arlanda case, along with extensive hydro-geological site investigations. This is likely to be necessary for any similar projects in Europe.

Specifi c for ATES projects, the water chemistry related to operational problems (corrosion and clogging) is of the utmost importance. In the Arlanda case, the water quality was found to be favourable. However, long term problems cannot be ruled out.

The predicted environmental impact is another important issue to consider at an early stage. In the Arlanda case the esker proved to have a favourable geometry that seems to limit the impacts to the surroundings. Indeed, the project was judged to be environmental favourable due to the drastic cut in harmful emissions it provides.

O. AnderssonSWECO Environment ABBox 286, 201 22 Malmö, [email protected]



Thermal Conductivity TestingThe soil’s thermal conductivity is a major factor in deciding the size

of the loop fi eld. Get it wrong and increased costs and problems

will follow. We asked an industry expert how to get it right.

Thermal conductivity testing (also known as thermal

response testing) is a critical step in the commercial

geothermal loop fi eld design process. The goals of the

test include measuring the undisturbed ground temperature,

calculating the formation thermal conductivity and possibly

estimating the thermal diffusivity.

While the ground temperature is something that we all

understand intuitively, the thermal conductivity and the

thermal diffusivity are a bit harder for most to comprehend.

In the industry we often use analogies to explain these two

values. Two popular ones are as follows: in the fi rst, one can

think of thermal conductivity as a series of rail cars in a train.

The higher the thermal conductivity, the greater the number

of cars. The thermal diffusivity is the locomotive. The higher

the thermal diffusivity, the greater the number of locomotive

engines that are pulling the rail cars. The second analogy is

slightly less abstract. Imagine putting a huge metal spoon in

a fi re. The higher the conductivity, the hotter the spoon will

get. The higher the diffusivity, the faster the heat will move

down the spoon and towards your hand. Regardless of

the analogy, accurate conductivity and diffusivity (and native

ground temperature) values

are essential for properly

sizing a geothermal loop

fi eld. Guessing these values

can lead to geothermal disasters: the system will either cost

too much to install or it won’t cost enough (and hence it will

be too short and underperform leading to possible failure).

The preferred way to determine these values is via an in situ

thermal conductivity test. This test can be thought of as

an MRI of the geological formation of interest. To conduct

such a test, a unit such as the GeoCube, manufactured

by Precision Geothermal, LLC, is essential. The GeoCube,

constructed of high grade aluminum, weighs only 54kg and

provides both strength and portability. A high powered unit,

in its default confi guration the GeoCube can measure the

conductivity in up to 225 meter deep boreholes. The rest of

this article describes how to use the GeoCube to conduct a

thermal conductivity test.

1) Drill a test bore to the target depth. The target depth

should be equal to the expected depth of the boreholes

in the fi nal installation. This is important because even in

the same formation, different depth boreholes can provide

different conductivity values. Install the U bend pipe. Let

the borehole sit for several days so that the soil reverts to

its native temperature.

2) On returning to the site with the GeoCube and a power

generator (the power generator should have a capacity

that is at least double the required kW of the test).

Attach the U bend pipe to the supply and return outlets

on the GeoCube. Insulate the exposed pipe so that it is

protected from the elements (thermally isolating the test

apparatus from the ambient environment is critical to the

data analysis).



3) Measure the temperature of the water in the U bend,

a temperature which refl ects the undisturbed ground

temperature. Add water to the GeoCube as necessary

via the open standing column.

4) Purge the system of air (this is a critical step).

5) Activate the GeoCube and turn on the appropriate

number of heating elements (aim for a heat fl ux of 45-75

watts/meter). Close the standing column.

6) Confi rm that the data logger and the data leads

are functioning properly. The GeoCube monitors

temperatures (up to 4 sensors), fl ow rate and power.

Confi rm that the GSM data function is active (GSM

enables remote monitoring of the test data, a feature

which is very convenient when the test site is far away

from your base of opertations).

7) Lock the GeoCube and let the test run for at least 50

hours. To avoid the risk of a curious onlooker disturbing

the test, consider displaying a sign that reads “Caution:

Sewage Test in Progress” or the like.

8). Return to the test site with your laptop. Transfer the test

data onto the laptop and using the analysis software

included with the GeoCube, calculate your thermal

conductivity. The analysis technique uses the industry-

standard “line source method.” Print a report and share

it with your colleagues and/or clients. Use the calculated

values to optimize the geothermal design.

The thermal conductivity test is a sensitive, scientifi c

analysis technique. While it is not diffi cult to conduct a good

test it is not diffi cult to conduct a poor test either. The most

common mistakes that people make include:

a) not purging the air out of the system properly;

b) not using a stable power supply.

c) failing to properly insulate the exposed piping.

d) failing to confi gure the data logger properly.

Each of these possible trouble spots is easy to avoid

with proper training. Precision Geothermal, LLC, the

manufacturer of the GeoCube, provides in-depth hands-on

training opportunities.

The fi nal issue of course is an economic one: what is

the market for TC tests and how much does a TC test

cost to run? The market for TC tests is growing in lock

step with the growth in the geothermal industry. Depending

on location owners of the GeoCube typically charge their

clients between 6,300€ and 10,500€ per test. At these

rates, most GeoCube users recoup their initial investments

in as few as four tests. Considering that some fi rms conduct

20 or more tests per year, the ROI can be exceptional.

If you have additional questions about thermal

conductivity testing, feel free to contact anyone at EGHSPA.

Also please note that if you wish to purchase a GeoCube,

visit www.precisiongeothermal.com for a custom quote and

don’t forget to ask for the EGSHPA discount before you

order.



RETROFIT - A case studyOld Charm with cutting edge technologyThe best of both worlds – to save the world!

WHY DID YOU CHOOSE TO UPGRADE YOUR HOME?

Ozzie and Mary Field own a typical Victorian terraced house in Bath. This is the story of their ongoing journey to ‘retrofi t their home’ and so live more lightly upon the planet.

We are doing a retro refi t ‘because we can’.“For us it was the ever-present and clear threat of climate change, with its effects felt particularly in the developing world that was the driving force behind the decision to reduce our carbon footprint. It is estimated that 300,000 deaths per year can be attributed to climate change. In parts of Africa the failure of rains and withering of crops refl ects the changing weather patterns which many scientists believe are the result of human behaviour. Moreover, the richest 20% of the world have already used up a third of the world’s resources. What positive action could we take?”

As we explored the processes we realized there are a great many attractive incentives in retrofi tting, such as the prospect of greater self reliance and reduced fuel bills. As time goes by we expect the price of fuel to go up. We are now on fi xed incomes so the proportion of our money required for fuel will increase. As we had already begun to downsize it seemed the most logical next step to increase our effi ciency.

HOW DID YOU START THE PROCESS?We began by considering building work to allow more sunlight into our new house. The back faces south, yet it was in use as a toilet and coal shed! This project slowly but surely expanded, until we found ourselves eco-refi tting the property. Mary says, “The easiest time to consider a full retrofi t of your property is when moving or working on your home”.

We decided to investigate similar schemes, although we did discover these were hard to fi nd. Eventually we had the precedents and contacts and had gathered all of the necessary information to get the ball rolling. As we progressed we found methods that had initially seemed straightforward, were often not! And experts disagreed! It was a steep learning curve.

Research was not easy, for example fi nding professionals who could explain to us what they could do to assist us were few and far between. We could not fi nd anyone in the Council to assist. Every year there is an Eco exhibition in London and we also went to one down in Exeter. Gradually we understood what could be done. There are two useful websites: the Camden project with a professor of London University, about a ‘Victorian house for the future (levh.org.uk),’ and T-Zero project which is an example of a retro fi t of a solid-walled property designed to achieve high levels of energy effi ciency with good insulation and sound workmanship - which is an outstanding project (tzero.org.uk).

When I asked builders how they kept their learning ongoing many said they wait for the Building Control Section of the Council to tell them. This is what makes Martin different (Martin Chandler of www.thecleanfootprint.com) – he actively seeks out new and developing techniques. So now we are happy to share what we have learnt.

WHAT WAS THE TIME SCALE?22/03/2010 - Commence Construction03/05/2010 - Commence Eco-Refi t08/05/2010 - Completed Construction13/06/2010 - Completed Eco-Refi t28/06/2010 - Move in!

CHOOSING THE TEAMNot all building professionals will be capable of undertaking and advising on such works - you must choose your team carefully and do your research.Ozzie and a friend visited a site in Penarth where the Clean Footprint Company were carrying out a complete retrospective fi tting to upgrade a house to modern standards for low heat use and low carbon emissions. Martin Chandler became the main contractor. He pointed out the wisdom of going for the most we can do, and not the minimum required by Building Regulations. It’s likely those regulations will be revised upwards in a few years.

WHAT MEASURES ARE YOU TAKING?Insulation, insulation, insulation! It’s the most cost effective way of reducing fuel bills - and not just in the roof space. It’s not so diffi cult to do the walls, and under the fl oor as well. Most heat loss is through the walls – about 37%! The Fields have solid walls (no cavity), so made use of Celotex or Kingspan, or similar products. The internet offers varied prices and the technical departments of these international suppliers are easily contactable. “I found I could telephone or e-mail them to unravel the jargon and complexity, and they helped by explaining what can be done – although you may have to be persistent.”

For example, we learned all about air tightness measures around open spaces and windows and the importance of mechanical ventilation and heat recovery. Once you have an airtight and draft free house you need ventilation - without letting warmth out. We now have a unit that does just that. It keeps the warmth in as stale kitchen and bathroom air goes



out, and uses it to heat the fresh air coming in. Thus you have controlled fresh and warm air. The importance of this was brought to our attention by Martin. But fi nding a supplier is not straight forward!

Another important aspect was having a highly effi cient gas fi re in the sitting room – necessary when instant warmth is required, perhaps when the baby wakes in the middle of the night, or one comes in soaking from the rain. So we are replacing the old but working model as it is reckoned to be only 40% effi cient.

Also, we now have:

• Solar panels to heat the domestic hot water. There is not room for both hot water and PV.

• A Condensing ‘A’ rated boiler (about 85% effi cient) replaced the back boiler (only about 40% effi cient).

• Zoning to use heat where it is needed and advanced heating controls which build in economies.

• Under fl oor heating (UFH) which requires lower temperatures and gives a comfortable all round warmth.

• A wood & multi-fuel stove for direct space heating. We were advised that wood burning stoves which heat water for the central heating are not allowed in smokeless zones. This we learnt too late is not true – but again, fi nding one was not easy.

• Triple Glazed windows with argon gas fi lling to achieve a U-value of 1.0.

• A fully glazed south side to allow solar gain and thermal mass to retain heat.

• And of course, low energy light bulbs and appliances.

We should of course point out that a variety of other measures can be taken and it is important to decide which is most applicable for a particular situations and individual circumstances.

• Other systems we considered but did not include:

• Solar power for generating electricity, ‘Photovoltaics’,

• Wind generation on an individual site or sited elsewhere and funded on a community basis.

• Ground Source Heat Pumps which gather heat from underground and through a heat exchanger provide heat for the heating system. They are suited to UFH.

• Air Source Heat Pumps which exchange warmer air for cooler air.

WHAT PROGRESS HAVE YOU MADE?Building works come fi rst and we are well advanced. These are to make the best use of the south facing aspect. The eco refi t is underway including all of the measures suggested in the SAP report. The builders are making great progress and we expect to move in by the end of June or at the beginning of July. The journey so far has been an educational and exciting experience. The ineffi cient gas boiler and living room fi re have gone. The solar panels are on the roof but laid upside down awaiting commissioning. The new boiler and tank and related kit are in position, and some radiators in place, with a gadget to deal with Bath’s hard water. The walls have new insulation. It is not necessary to remove plaster; but in our case the plaster was unsound so it was easy to do and gave us another inch of space. The covings and woodwork around the windows have been removed (with care) and set aside for re-fi xing. The roof rafters have been deepened by a couple of inches to take thick insulation board. We found that existing insulation in the roof on the ceiling joists was poorly installed and patchy so the benefi ts were lost as warm air simply fi nds a way out. The re-roofi ng done a few years ago turns out to have been poorly done so we had an unexpected extra expense. The contractors have cleaned the removed stone for reuse.

HOW WILL THIS BENEFIT YOU IN THE FUTURE?“As we are concerned about our negative effect upon the world we are glad to have the chance to reduce our footprint. A good measure of this is the Code for SustainableHomes, which rates buildings holistically.” The ffi elds are aiming for Level 5 of the energy sections of the code. More likely they will reach level 4, at least 40% better than current building regulations. “Overall we hope for an improved quality of living, for ourselves and, ideally, globally!”

This is an idea embodied in the Transition movement principles: moving from an unsustainable way of living and using better the Earth’s resources. “We are convinced that this is a worthwhile investment. There will be energy savings, lower emissions and a reduction in associated costs. “With energy effi ciency and carbon environmental impact going up the ffi elds are working towards a future for all.

This will require additional adjustments to their lifestyle, regarding transport and patterns of food consumption – other aspects of the Transition’s movement programme. It fi ts also with our National policy. “The surest way to increase energy security is to design for less energy consumption in the fi rst place. Energy conservation measures which can result in signifi cant fi nancial savings, higher comfort levels and health benefi ts for UK citizens.”

CONTACTS Ozzie ffi eld 01225 314 345.Contractor: The Clean Footprint - Martin Chandler: 07814 158 621South West Heating; Fair Energy; and Newman [Electrical] Services.

Article based on a report by Jonathan Robert Evans. If you would like any further information please contact Ozzie.




Your “personal” assistanton siteWhy should you bother with an iPhone, iPad or a BlackBerry - after all, they’re just fancy mobile phones for kids right? Not quite – the use of so-called Smartphones or Personal Digital Assistants (PDAs) has been on the rise for some years now ever since these devices learned to aggregate several services into one attractive package. Adrian Bridgwater goes searching among the iPhones and BlackBerrys for the perfect digital pal and looks at some of the key features (and pitfalls) to look out for.



My fi rst Personal Digital Assistant (PDA) was a green screen unit of dubious quality, it had a diary and played a passable version of Space Invaders and that‘s about all I remember. What I can

tell you is that that was nearly 15-years ago, so you can imagine the progression path that this technology has been on over that time period.

Colour screens happened somewhere around a decade ago and this made all the difference to the look and feel of these shiny little blocks. But the single biggest development was surely the arrival of what I will

simply call ‚connectivity‘ i.e. the ability to connect to voice and data networks so that suddenly phone calls and emails were all possible from one tidy unit - that still played Space Invaders if you absolutely insisted.

Today many of us take the BlackBerry and other ‚connected device‘ such our iPhone largely for granted. The BlackBerry started off life as a two-way pager way back in 1999. Improvements kept coming and by 2002 the BlackBerry featured email, text messaging, web browsing, voice communication and even an Internet faxing function using the same wireless data transmission infrastructure and system as mobile phones.

Developed by Canadian company Research in Motion, the BlackBerry was named after the tiny but handy little keyboard on its front panel, which resembles the bobbles on the outside of the fruit of the same name. Most BlackBerry Smartphones now even include a media player and camera so you really have everything you need in one stylish device.

Such is the love and adoration people reserve for their BlackBerrys that a whole subculture has developed to support the needs of the device‘s afi cionados who can often be heard referring to their addition as – their ‚CrackBerry‘. Madonna has been rumoured to sleep with hers under her pillow so she can stay in touch - and judging by the ‚fi rst lady‘ of pop‘s antics in recent years it may be true. More sobering is the suggestion that after the twin towers were attacked on 911 in New York the phone lines went down, but some people trapped in the rubble were still able to

send GPRS messages over their BlackBerry networks at the time. Although that may be an urban myth!

The new BlackBerry Curve 8900 is a real gem and it can save your bacon if you (like me) fi nd yourself in the most unpredictable of scrapes time and time again.

So there I was at 5am after the most amazing party I had even been to and I stumbled out onto the road to try and fi gure out where I was. The streets around me looked completely unfamiliar and in between a hangover and a bad case of ‚cotton-wool mouth syndrome‘, I was starting to panic if I am honest.

Then I remembered I was taking the BlackBerry Curve 8900 unit for a test drive to write this feature and so I quickly booted up the BlackBerry Maps application (which is pre-installed) and got connected via the mobile network to determine where I was. The best thing about this is that the GPS (Global Positioning System) inside the BlackBerry was able to get a fi x on exactly where I was and the unit even gave me a route planner to fi nd my way home. Now that is what I call a smart Smartphone!

The great thing about modern digital cameras is that they are so small and powerful and they fi t in your pocket. The bad thing about modern digital cameras is that you have to remember to take them with you wherever you go. Somehow we all manage to remember our mobile phones though don‘t we? When our mobile phone has become our BlackBerry or our iPhone it‘s OK though – because today they come with nifty cameras that boast pretty reasonable megapixel quality.

With something around 3.2 megapixels now being quite standard for Smartphone cameras, ultra-bright LED fl ash and ‚superfi ne‘ settings should allow you to even take pictures in dark pubs and clubs should you so wish. All you‘re going to need to transfer pictures to your computer is a USB lead and most of us have one of those kicking around somewhere.

When it comes to uploading your photos, this can sometimes be a bit of a nightmare. By downloading the dedicated ‚Facebook for Blackberry‘ application to your device, you get pretty much full access to your Facebook profi le and your others pages directly from your handheld. OK you could use a browser, but this is unbelievably quick (if you have a nice network connection) and it automatically refreshes once you have uploaded your content.


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Nearly Fifty PercentEnergy From Renewable Sources By 2030Up to 45% of our energy should be created through renewable energy sources by 2030 according to a report from the UK’s Committee for Climate Change (CCC).

EGSHPA fi nds this news both encouraging and compelling, but wonders whether the practical roll out and deployment parameters of such projects have been completely thought through.

The committee was asked to look into a low carbon future by the British coalition government shortly after they took power and has now delivered its fi ndings.

The report recommends that 30% of the UK’s energy should be generated by renewable sources, with the scope for 45% of the energy coming from renewable sources depending on how much the cost of the technology falls.

Currently there is government support for renewables up to 2020 due to European Union targets — and the government are being urged to commit their support to renewable energy sources past this date.

EGSHPA is hopeful that ground source heat pump technologies will form part of the plans, which drive roadmaps being drawn up to meet the challenges of the next two decades.

One of the other main sources of energy that the committee recommends is biomass. This involves the use of renewable materials such as wood pellets as fuel, and is a carbon neutral form of generating energy.

Biomass can be used in a range of properties and is ideal for use in the home.



Hands on introduction to modelling with FEFLOW

Shrewsbury on 26th & 27th OctoberHands on introduction to modelling with FEFLOW: 26th October 2011This course gives an introduction to groundwater modelling using the simulation system FEFLOW. On the basis of an example, delegates build up a three-dimensional flow and transport model applying the most important program functions (preprocessing, simulation, results evaluation).FEFLOW is a finite element software package for modelling fluid flow and transport of dissolved constituents and/or heat transport processes in the ground. The finite element discretisation enables the user to build complex unstructured meshes that closely match natural structures while obeying the requirements such as element size, element angles, etc.

FEFLOW applications include:• Groundwater protection zones• Salt water intrusion• Groundwater remediation• Groundwater-surface water interaction• Geothermal energy production• Mine dewatering• Dam seepage• Fracture and fissure flow and transport

The main topics covered in the course are:• Introduction to flow and mass transport simulation• Introduction to the FEFLOW Graphical User Interface• Setting up a 2D and 3D flow model• Extension to a transport model• Pre and post processing

Focus on FEFLOW modelling for Ground Source Energy: 27th October 2011NEW FOR 2011, ESI in conjunction with DHI-WASY, will present a ground source energy (GSE) modelling workshop aimed at those involved in the design, specification and installation of GSE schemes. In particular, those who want to model the energy source – the most critical aspect of the scheme.

In many cases closed loop GSE systems offer the most appropriate solution. In aquifer settings, significant benefits may be obtained by accounting for the improved performance of borehole heat exchangers (BHE) in the presence of groundwater flow which will dissipate heating or cooling loads applied to the ground system. Accounting for this requires the use of 3D coupled groundwater and heat flow models of the aquifer system.

FEFLOW modelling software integrates BHEs via linear elements and allows full coupling between the GSE scheme and the hydrogeological setting. For larger schemes where the building overlies an aquifer, open loop GSE schemes may offer a significant improvement in performance.

The course will provide an introduction to the theory underlying ground source heating and cooling and geothermal schemes, and the UK regulatory context, to help delegates:• model realistic GSE ground loop in a realistic geological setting;• predict the GSE system performance;• design and optimise GSE schemes;• obtain regulatory approval for open loop schemes.Real Case studies will illustrate FEFLOW’s new capabilities to model both open loop and vertical borehole closed loop GSE heating and cooling schemes for complex UK aquifer settings.

To book a place on the Practical Training in FEFLOW course:

www.egshpa.com/practical-training-feflowEmail: coursesuk-esinternational.com

Documents

Ground Up Magazine - Issue 2 Website