Ground Up Magazine - Issue 2 Website

Ground Up magazine issue 2

EGSHPA European Ground Source Heat Pump Association

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

Ground Up magazine 5.99â‚Ź 3

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EGSHPA European Ground Source Heat Pump Association

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Ground Up l October 2011

EGSHPA European Ground Source Heat Pump Association

Welcome 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.

European Ground Source Heat Pump Association Argyle House Dee Road Richmond Surrey TW9 2JN Not for Profit Company Limited by Guarantee, Registered in England & Wales, Company No. 7689830 Homepage: www.egshpa.com

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.

Contact Us: Membership@egshpa.com

So enjoy the second issue of Ground Up magazine and remember to email us membership@egshpa.com if you have any submissions you would like to see featured in the next issue.

Paul Kilby Editor

Inside

Richard Layton Head of Finance richard.layton@egshpa.com

Making the Case

The Team Adrian Bridgwater Head of Social Media & Editor-in-Chief adrian@egshpa.com

Dale Holdback Technical and Industry Knowledge dale.holdback@egshpa.com

How to achieve the best, efficient and affordable systems for clients

Nathan Berkley Head of Media and Marketing membership@egshpa.com

Numerical models

We would also like to thank the following companies who supplied fantastic content for this issue:

How hydrogeolgists and numerical models can assist design

Natural Born Driller Making sure the drilling process is correct

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

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

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

Gadgets Whats the best personal assistant on site

Retrofit

• 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 Disclaimer Ground 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.

A glimpse into a retrofit project

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EGSHPA European Ground Source Heat Pump Association

Making the Case I

ts been my observation that before any marketplace will fully embrace GSHP all stakeholders must be genuinely convinced of its benefits. 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 artificially 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/benefit 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 find 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 five 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

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3. Maintenance & Repairs - Cost

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EGSHPA European Ground Source Heat Pump Association

4. Life Cycle Replacement - Cost 5. Savings - Benefit 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 Coefficient 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 flush 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 efficiency is important it is only one component determining the system efficiency. We need to move circulation fluid 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 efficiency, 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.

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 figures 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 financing models even for private home owners. They are making very big profits and still saving homeowners energy dollars too.

A final note. To achieve the best, honest, efficient 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 Certified 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 don@geothermal.co.il.

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

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EGSHPA European Ground Source Heat Pump Association

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

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rchitects 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 benefits to the overall design of GSE schemes. The degree of complexity is generally proportional to the scale of the proposed scheme. Smaller schemes benefit from simple tools that are based on simplified underlying conceptual models, while larger and more complex schemes benefit from numerical models that can account for more complex ground and/or operational conditions.

The effects of groundwater flow 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 flow will vary: BHEs that operate with heat extraction or injection only are typically more sustainable in the presence of groundwater flow; groundwater flow may not benefit 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.

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Closed loop schemes Understanding 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 confidence 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.

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Detailed distribution of properties within the borehole array allows all interference effects to be calculated specifically for the proposed design. FEFLOW can also represent the effect of groundwater flow 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 significant 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 significantly 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 configurations where energy loads are significantly 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 efficiency when compared to the boreholes around the margins. Quantifying scheme performance allows alternative, sustainable and more optimal borehole configurations 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 ďŹ 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.

EGSHPA European Ground Source Heat Pump Association

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 efficient solution to be used in order to have confidence in the long term. Visualisation of the results with threedimensional 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 confidence in the performance of the scheme.

Open loop schemes Open 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 benefits of having suitably qualified 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 flexibility in representing and assessing the feasibility of the proposed medium to large GSE schemes when compared to simpler tools.

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

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 efficiency 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 identification 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.

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

A significant 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 quantified using modelling in the design of open loop GSE schemes.

In this article we have provided some insights into the need for having a scientific, 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 scientific 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 info@esinternational.com tel. +44 (0)1743.276100

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EGSHPA European Ground Source Heat Pump Association

Natural Born Driller As 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 …

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he green credentials of ground source heat pumps are already well known and accepted, but for many considering them, the financial 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 justified, 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.

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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 specific’. 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.

• Also, explain the need to avoid siting boreholes anywhere near large trees whose subsequent root growth may damage the loops.

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

• Planning permission is of course an obviously necessary step, but might there be any problems connected to the noise produced by drilling? Worth mentioning.

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

• Might the specific 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

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

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EGSHPA European Ground Source Heat Pump Association

• The importance of backfilling 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 - efficient 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.

• 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 benefits 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.

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

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EGSHPA European Ground Source Heat Pump Association

Ground Source Energy System

HIGHLIGHTS • Gross area 560,000 ft2.

• Net office 340,000 ft2.

• Nett retail 220,000 ft2.

One New Change is Land Securities’ latest development

• Total cost – £540m.

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 flagship menswear and womenswear fashion brands, all overlooking London’s most famous landmark, St Paul’s Cathedral.

• Area equivalent to 12 football pitches • One of the largest office floor 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.

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EGSHPA European Ground Source Heat Pump Association

The Building One New Change is a contemporary building with a total of eight floors comprising offices on the top four floors, a public terrace at roof level on the sixth floor, and shops on the Lower Ground, Ground and First Floor. With around 60 stores spanning the three floors, 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.

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 >

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 efficiency through the use of largescale 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

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EGSHPA European Ground Source Heat Pump Association

Ground Source Heat Pump System Schematic

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

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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 fluid within the pipes is warmer than the surrounding air.

Continued on page 14 >

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EGSHPA European Ground Source Heat Pump Association

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EGSHPA European Ground Source Heat Pump Association

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 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

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.

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

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.

The piles were drilled to the required structural depth.

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There is a pump in each Well in a duty & standby configuration.

EGSHPA European Ground Source Heat Pump Association

Reference: Geothermal International Ltd. Spencer Court 141-143 Albany Road Coventry CV5 6ND United Kingdom T: +44 (0) 24 7667 3131 enquiries@geothermalint.co.uk www.geothermalint.co.uk

Hoare Lea Glen House 200-208 Tottenham Court Road London W1T 7PL Tel: 020 7890 2500 london@hoarelea.com www.hoarelea.com

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EGSHPA European Ground Source Heat Pump Association

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.

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have been following EGSHPA on Twitter since the organisation first 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 specifically agreed remit to educate geothermal installers and industry related professionals.

I was involved with a ground source heap pump (GSHP) installation company some five 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 profitable 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 first 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 configuration” 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

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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 first 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 find 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 -

EGSHPA European Ground Source Heat Pump Association

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 dissatisfied 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 flow 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 flow 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 finished.

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 efficient 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.

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EGSHPA European Ground Source Heat Pump Association

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?

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n 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.

Introduction The 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 efficiency 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 figure 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 flow 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.

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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 System The 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 figure 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 flow of the ATES system will be reversed and the

EGSHPA European Ground Source Heat Pump Association

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 figure 1, there are five 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 filter completion�. These types of wells are developed by air lifting, or hydro-jetting, in order to wash out fines and accumulate coarse particles around the wells screen (natural development), see figure 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-infiltration pipes. To regulate the production flow, 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 Geometry Originally, 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, figure 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 HalmsjĂśn - 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 figure 4. This was useful for the project since the

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EGSHPA European Ground Source Heat Pump Association

bedrock seems to be practically water tight. Also, the slopes of the esker are often dressed with fine-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 Properties The ground water level in the esker is practically flat 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 flow 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 infiltration. For this reason there are six wells in the south in order to spread the infiltration 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 fine grained sediments towards east has a estimated k-value in the order of 5Ă—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 fine 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).

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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 significant difference between north and south concerning the content of dissolved carbonates. In the north the hardness is 16 odH. In the south this figure 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.

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EGSHPA European Ground Source Heat Pump Association

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 operation In 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 flow rates in both directions (the summer and winter modes).

The summer situation was at a flow of 270 m3/h (200 l/s), illustrated in figure 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 reflects 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 influenced area substantially.

It was also shown that Lake Halmsjรถn has a limited influence on the hydraulics, probably due to fine grained sediments at the bottom of the lake.

Conclusion The 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.

Specific 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. Andersson SWECO Environment AB Box 286, 201 22 Malmรถ, Sweden olof.andersson@sweco.se

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EGSHPA European Ground Source Heat Pump Association

Thermal Conductivity Testing The soil’s thermal conductivity is a major factor in deciding the size of the loop field. Get it wrong and increased costs and problems will follow. We asked an industry expert how to get it right.

T

hermal conductivity testing (also known as thermal response testing) is a critical step in the commercial geothermal loop field 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 first, 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 fire. 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

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ground temperature) values are essential for properly sizing a geothermal loop field. 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 configuration 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 final 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).

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EGSHPA European Ground Source Heat Pump Association

3) Measure the temperature of the water in the U bend, a temperature which reflects 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 flux of 45-75 watts/meter). Close the standing column.

6) Confirm that the data logger and the data leads are functioning properly. The GeoCube monitors temperatures (up to 4 sensors), flow rate and power.

Confirm 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 industrystandard “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, scientific analysis technique. While it is not difficult to conduct a good test it is not difficult 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 configure 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 final 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 firms 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.

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EGSHPA European Ground Source Heat Pump Association

RETROFIT - A case study

Old Charm with cutting edge technology The best of both worlds – to save the world!

Ozzie and Mary Field own a typical Victorian terraced house in Bath. This is the story of their ongoing journey to ‘retrofit their home’ and so live more lightly upon the planet.

WHY DID YOU CHOOSE TO UPGRADE YOUR HOME? We are doing a retro refit ‘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 reflects 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 retrofitting, 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 fixed 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 efficiency.

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 ecorefitting the property. Mary says, “The easiest time to consider a full retrofit 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 find. 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 finding professionals who could explain to us what they could do to assist us were few and far between.

We could not find 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 fit of a solid-walled property designed to achieve high levels of energy efficiency with good insulation and sound workmanship which is an outstanding project (tzero.org.uk).

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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 Construction 03/05/2010 - Commence Eco-Refit 08/05/2010 - Completed Construction 13/06/2010 - Completed Eco-Refit 28/06/2010 - Move in!

CHOOSING THE TEAM Not 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 fitting 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 difficult to do the walls, and under the floor 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

EGSHPA European Ground Source Heat Pump Association

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 finding a supplier is not straight forward!

Another important aspect was having a highly efficient gas fire 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% efficient.

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% efficient) replaced the back boiler (only about 40% efficient).

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

• Under floor 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, finding one was not easy.

• Triple Glazed windows with argon gas filling 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.

WHAT PROGRESS HAVE YOU MADE? Building works come first and we are well advanced. These are to make the best use of the south facing aspect. The eco refit 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 inefficient gas boiler and living room fire 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-fixing. 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 benefits were lost as warm air simply finds a way out. The re-roofing 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 Sustainable Homes, which rates buildings holistically.”

The ffields 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 efficiency and carbon environmental impact going up the ffields 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 fits also with our National policy.

“The surest way to increase energy security is to design for less energy consumption in the first place.

Energy conservation measures which can result in significant financial savings, higher comfort levels and health benefits for UK citizens.”

CONTACTS Ozzie ffield 01225 314 345.

Contractor: The Clean Footprint - Martin Chandler: 07814 158 621 South 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.

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

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EGSHPA European Ground Source Heat Pump Association

Your “personal” assistant on site Why 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 socalled 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.

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EGSHPA European Ground Source Heat Pump Association

M

y first 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 aficionados 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 ‚first 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) find 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 figure 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 fix on exactly where I was and the unit even gave me a route planner to find 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 fit 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 flash and ‚superfine‘ 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 profile 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 Percent Energy From Renewable Sources By 2030 Up 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 finds 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 findings.

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.

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Hands on introduction to modelling with FEFLOW Shrewsbury on 26th & 27th October Hands on introduction to modelling with FEFLOW: 26th October 2011

This 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 2011

NEW 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-feflow Email: coursesuk-esinternational.com