Geo thermal heating

[Athene]

I have researched past posts and although other people have been interested in this system in 2005, I wonder if anyone actually installed it? If so I would like to hear from them as to whether it is as efficient and cheap to run as the installers claim. If what they are saying is true then after three years one would make up the initial outlay as compared to what would be the cost to continue with propane!

[Gluestick]

I looked at it very carefully indeed.

The conclusion was that to be effective, it must be underfloor. Having an established house with fine tiled floors, ripping this all up was not a viable option.

Additionally, once I ran a Cost-Benefit Analysis and a DCF (Discounted Cash Flow) projection, it became apparent that the front end capital cost, amortised over the life cycle of the equipment, meant that unless one lives for 120 years, (and the capital plant last far longer than can be realistically expected), installing geothermal shows no actual cost advantage over (e.g.) oil fired, even with the increased cost of oil and in fact financially is disadvantageous in most cases.

However,

I am carefully montotring a chum's place in Wales. This is a barn conversion with a new underfloor system and deep boreholes for the geothermal collectors.

He has promised me electricity consumption and costings probably for the coming Winter, as work was still going on last Winter with contractor's plant burning significant amounts of power and was thus not representative of heating costs.

He still needs subsidiary heating, BTW: his is a wood burner.

 

[WJT]

I have just followed Clair's link on Normandie's post regarding geothermal threads and found this one. Out of interest Gluestick, were you able to get an update of your friend's system?

Unfortunately, I don't think it would be very viable for us because we have mostly iron radiators and no possibility of under floor heating. However, I have been told that this would not be a problem by someone that installs the systems. Does anyone have any experience of this and any idea of installation cost?

[powerdesal]

[quote user="Gluestick"]

The conclusion was that to be effective, it must be underfloor. Having an established house with fine tiled floors, ripping this all up was not a viable option.

Additionally, once I ran a Cost-Benefit Analysis and a DCF (Discounted Cash Flow) projection, it became apparent that the front end capital cost, amortised over the life cycle of the equipment, meant that unless one lives for 120 years, (and the capital plant last far longer than can be realistically expected), installing geothermal shows no actual cost advantage over (e.g.) oil fired, even with the increased cost of oil and in fact financially is disadvantageous in most cases.

However,

I am carefully montotring a chum's place in Wales. This is a barn conversion with a new underfloor system and deep boreholes for the geothermal collectors.

He has promised me electricity consumption and costings probably for the coming Winter, as work was still going on last Winter with contractor's plant burning significant amounts of power and was thus not representative of heating costs.

He still needs subsidiary heating, BTW: his is a wood burner.

[/quote]

Gluestick,

I am going round in circles on the "best heating question". I take your point about the cost analysis aspect of GSHP kit. Especially as Jonzjob quoted E16,000 just for a borehole.

What route did you finally take?

I seem to recall that you had some air source individual room units in the end. Are they effective, and would you recommend them (without prejudice)?

I reckon that I would need 8 individual units of varying sizes but have not had any luck finding on the net.

I am in a similar position of not being willing to rip up existing tiled ground floors to install UFH which, I think, is a very expensive installation anyway, having priced up the various zone valves etc necessary. The bedrooms are wooden plank flooring on top of the exposed beams so cant be UFH anyway.

Do you know of any air source system which produces a wet output to be piped to fan-coil units as opposed to oversize panel rads ? Would that idea even work?

I am thinking along the lines of using the existing normal wet CH pipework (PEX/PER) and scrapping the "as-yet-unused" panel rads that are already in place.

So many questions - my brain 'urts.

[Gluestick]

Steve:

At present, all we have is an older Deville diesel burner, which acts as a (very expensive!) space heater, a woodburner (Big One!) and electric room rads of circa 2,400 Watts each.

At the moment, since most of our time is still, regretfully, spent in the UK working, it's not much of a problem: it will be, however when we migrate!

You have reminded me to chase my chum for some data: will do and revert.

I am also now looking at the viability of using off peak electricity with a large thermal store, for both DHW and CH, as whilst EDF stick to their statutory supply contract it very much looks the cheapest option.

How's Sharja Next The Sea?

 

[:)]

[powerdesal]

GS,

Sharjah is getting hotter now that the winter is over, also the air pollution is becoming an ever greater concern. Traffic is increasing dramatically and all prices are rising with a reported inflation figure of 30% in 2007 with probable 40% in 2008. The value of the USD is having a drammatic effect.

Apart from that, everything is peachy!!!!!!!

Do you have thoughts on the thermal store design or have you got an "off the shelf" unit in mind. I must admit to being tempted along those lines with a heating coil input from evac tube solar as well as leccy (off peak). I see a need for SUBSTANTIAL amounts of insulation to the storage , under, round and above. Do such stores exist? Perhaps a small air source heat pump inlet could also be incorporated, it would only mean another tapping and coil.

[Gluestick]

Glad things are well in Sharja, Steve! 30-40% inflation! Wow

I am still evaluating thermal stores. The core problem for me of all green systems in the UK, and elsewhere, it seems is that time and again, it's a rip off!

China is now manufacturing the latest evacuated tubes and thin film PV and the prices are tumbling, in real terms - excluding the also tumbling US$!

The TSs I have looked at thus far seem to enjoy excellent insulation. I would probably also super-insulate the space in which the TS sat; as you say, top, bottom and sides!

My problem is that in the North, whilst sun energy is good Summer, late Spring and early Autumn, it's not enough for CH when one needs it!

The secret to all this is going to be the control systems: one central ECU (Microcontroller based??) should, eventually be able to control the whole kit: back to my favourite; systems integration.

One can buy all the component bits quite cheaply: it's knitting it all together effectively that's the current challenge!

I am thinking that one TS should be able to have perhaps two calorifiers and the system "Chose" which is the best heat input source at that moment: solar; ground source; air source; mains electricity; whatever. Intelligent control and diverter/motorised valves achieve the objective simply and cost-effectively.

I'm still thinking and researching!

Over Easter I am also going to go and see a reputed wood fibre processing plant nearby, for prices, quality and etc and then think seriously - again -  about a wood/bio fuel burner which may well be the answer.

 

 

[Gluestick]

I promised these figures previously, now I have them!

This is for a total refurb, underfloor heating in Wales which is not a warm place!

Geothermal using boreholes.

So, as I’ve said our single story cottage is approx 1900 squ ft. Insulation is basically stone walls with lime mortar 18” to 24” thick.

The a 2” air gap to permeable building paper attached to a timber frame with 50mm celatex under plasterboard. Half the building is normal ceiling height while the remainder is open plan 16 foot to eaves. Total Energy bill per annum is £1800. I’ve subdivided it up as follows.

 

Jacuzzi heating and filtration.   £400        35degC operates 24/7/12

Workshop power & light.          £150        Welding, compressed air, battery charging etc.

General Household.                £100         Computer, TV, domestic appliances etc.

Cooking.                                £150       

Heating & Hot water               £1000       Main room stats set at 18degC, Bedrooms 17degC. Hot water 49degC. Anti    

                                                            Bacterial High hot water set for 60degC every 30 days. Wood burner (12kw) used in open

plan area in the winter evenings. We have to be careful we don’t over do the wood burner

as it easily gets too hot!

 

Hope this helps ~~~