We are tinkering about the idea if running our CH (and DHW) from a Ground Source system with a bore hole. I have the calcs for the rads using a conventional system. Is there a rule of thumb that using ground source (at al lower temp.) needs 20%, 30% ????% bigger rad??????????
Ground source systems
- Thread starter David E
- Start date
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Two bore holes 
Lots of things to consider before you start.
The rads should be 20/30% bigger than a conventional system, or better still consider underfloor heating for an ideal solution.
Insulation is a priority before anything, and must be up to current standards or you will be wasting your time.
DWH will depend on usage, and unless you can store masses of hot water it's unlikely the heat pump will supply, so an alternative back up system is essential.
For more info send me an email (in my profile)
Lots of things to consider before you start.
The rads should be 20/30% bigger than a conventional system, or better still consider underfloor heating for an ideal solution.
Insulation is a priority before anything, and must be up to current standards or you will be wasting your time.
DWH will depend on usage, and unless you can store masses of hot water it's unlikely the heat pump will supply, so an alternative back up system is essential.
For more info send me an email (in my profile)
All new rad lists give heat output @ 50C which is fine. Only a few of the latest heat pumps will deliver water higher than this. You may well want to supplement with Solar for dhw.
Bore holes usually about 200ft deep or if you have enough area cound dig out garden to a depth of 1.8 m and lay pipes in this.
Bore holes usually about 200ft deep or if you have enough area cound dig out garden to a depth of 1.8 m and lay pipes in this.
Information that you should treat with some suspicion, since it's not published here for anyone else to validate.doitall said:
Meanwhile...
[url=http://groundreach.fiz-karlsruhe.de/en/aktuell/kat1/akt45.html]The GROUND-REACH project[/url] said:
and see this: http://www.gshp.welwyn.org.uk/church_heating.asp
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you do talk some balls on occasion
the scruff does not need to validate anything he is well respected in this industry
Unfortunately there are many difficulties with heat pumps. The major being the low output temperature delivered. The highest efficiency is only obtained with lower temperatures.
One of the biggest problems is the over enthusiasm of those selling it and extolling its advantages and hiding its many disadvantages.
Its most useful with UFH but even so its not usually possible to use it for heating without supplementary fuel use to about 25%.
The biggest fallacy is the efficiency on carbon generation. It little more carbon efficient than a gas boiler but thats conveniently forgotten by those selling them.
Another difficulty is the unit life to be expected. Its a lot of money to be put into a unit without a long term guaranty.
Tony
One of the biggest problems is the over enthusiasm of those selling it and extolling its advantages and hiding its many disadvantages.
Its most useful with UFH but even so its not usually possible to use it for heating without supplementary fuel use to about 25%.
The biggest fallacy is the efficiency on carbon generation. It little more carbon efficient than a gas boiler but thats conveniently forgotten by those selling them.
Another difficulty is the unit life to be expected. Its a lot of money to be put into a unit without a long term guaranty.
Tony
I didn't say that he did.kevplumb said:
I'm sure he is, but he's not always right either, viz:
//www.diynot.com/forums/viewtopic.php?p=387539#387539
I am on the PCC for our local church, an ex science teacher Church Warden had all the old ladies bleary eyed about his wonderful idea to pay some £25,000 to heat the Church for future parishoners via this method, citing the wanderful fuel saving and no emissions at all. I sat quietly until he finished.
Then I did my Mr unpopular act and told them the other side of the story.
In my view for the church cheap wall heaters are the best option taking into account environmental considerations, installation costs, cost of capital and running costs.
I expect the old ladies will vote for him and spend money that could be better used in Darth Voor on a state of the art heating system for our cosey littly holy huddle, which is quite honestly managing perfectly well wearing overcoats on the very few hours a week the church is used.
Then I did my Mr unpopular act and told them the other side of the story.
In my view for the church cheap wall heaters are the best option taking into account environmental considerations, installation costs, cost of capital and running costs.
I expect the old ladies will vote for him and spend money that could be better used in Darth Voor on a state of the art heating system for our cosey littly holy huddle, which is quite honestly managing perfectly well wearing overcoats on the very few hours a week the church is used.
Softus said:
Unlike some I'm not allowed to advertise so if you want the web site then ask like everyone else.
Better still, like the energy show the other week, we will be at the Bath and West show in a couple of weeks, and as before we will have the only working model.
If you want any free entry tickets do ask.
Went to the energy expo at Olympia not so long ago... 90% bulls**t. Very few companies really knew the true energy savings (if any) and the real green credentials of their products.
Unless installed in the correct environment ie very high insulation, double space underfloor heating AND green sourced electricity (at higher cost of course) thery are a con. I found only one company with any ethics (I think it was Eco-Hometec) and the rep was a qualified thermodynamics engineer. It was a pleasure to talk to someone who knew the truth behind these systems. Leave them in Scandinavia where they work well.
For a church that probably has old sectional radiators a very high thermal mass and is used only a few times a week its a waste of time installing expensive GSHP.
That church estimated the cost to be £60-£80,000 - I suspect high mounted infra red heaters (running on green electricity or gas) would have been a much better bet and more reliable.
Unless installed in the correct environment ie very high insulation, double space underfloor heating AND green sourced electricity (at higher cost of course) thery are a con. I found only one company with any ethics (I think it was Eco-Hometec) and the rep was a qualified thermodynamics engineer. It was a pleasure to talk to someone who knew the truth behind these systems. Leave them in Scandinavia where they work well.
For a church that probably has old sectional radiators a very high thermal mass and is used only a few times a week its a waste of time installing expensive GSHP.
That church estimated the cost to be £60-£80,000 - I suspect high mounted infra red heaters (running on green electricity or gas) would have been a much better bet and more reliable.
Gasguru said:
Have to agree with some of your points gasguru, at the N EC the other week, some of the claims were laughable 8-1 COP for example, another had a gadget the size of a microwave, that would heat the whole house
Why you think the technology would work in Scandinavia and not this Country is interesting, a typical comment from someone who knows very little about the subject.
We are the sole UK distributors for the market leaders in heat pumps, and I can assure you they work very well and do what they say on the can. They are also very reliable, they have to be as we use the same technology for multi-million pound industrial cooling plant.
doitall said:
I am not aware of any GSHP manufactures that quote a realistic seasonal average COP - they always quote the highest achievable ie at a low delta T. We need a "SEDBUK" type rating since many systems with radiators will actually have a very low COP in the middle of winter and the initail apparent savings are just not realistic.
Very few manufacturers tell the customer you must use electricity generated from renewable energy (at higher unit cost) - highly unethical.
Running a modern well installed and setup boiler will achieve efficiencies of say 90% from its gas energy source. Running a heat pump from fossil fuel derived electricity will offer no more efficiency and quite possibly be more wastefull. Electricity generation is only 32% efficient so even with a best case scenario COP of 3 or 4 we are no better off. You are throwing away 68% of the heat energy (to generate the power) into the air before it gets to your home.
In Scandinavia and Northern Germany (where I am led to believe these systems were developed and are popular) 80% of their electricity is generated from "green" sources ie hydropower. Fossil fuels are only used during mild winters when meltwaters are low and hydropower must be supplemented. Therfore electricity has little impact on the environment through CO2 emmisions.
In this country however the reverse is true - 80% of our electrical energy is generated by burning fossil fuels at a very low efficiency level (approximately 32%) ie 68% of the fuel heat energy is wasted.
In reality the the heating industry is blighted with many products that do not serve the customer or the environment well - due to the ignorance of the public but especially the heating installers who do not fully understand these products. If they did many manufacturers would cease to trade as there propagander and greenwashing would not stand up to scrutiny. Examples Ideal boilers, Baxi boilers - anyone half decent in this trade would never install them but these companies survive. Gripe over
doitall...Do you make it very clear to your customers that they must buy electricity from a genuine green energy source? and that the high COPs are only achievable with low output temperatures ie underfloor heating with much higher pipe lenghts than normal.. and they must have the the property insulated as well as possible?
What manitenance is required and at what cost? I can't beleive any systems are truly maintenance free. None of my customers with condensing boilers are saving a penny once proper annual servicing and repair costs are taken into account.
I have a relative installing GSHP system. The ground loops were laid last week.
All 720m of the stuff. Three loops of 40mm pipe 240m long.
Its the installers second install.
Horizontal loop that is. They mostly do bore wells.
Scroll compressors are the norm in these systems . About a 20 year life span with good care. If you look inside the casing on one of these units it will probably be a copeland compressor of one kind or another.
Some of the manufacturers ( maybe copeland I think) have a video of someone running the compressor dry and rolling a handfull of ball bearings into the inlet port to which the compressor spits them out the discharge side at high velocity without causing any harm to the scrolls inside the compressor.
All 720m of the stuff. Three loops of 40mm pipe 240m long.
Its the installers second install.
Horizontal loop that is. They mostly do bore wells.
Scroll compressors are the norm in these systems . About a 20 year life span with good care. If you look inside the casing on one of these units it will probably be a copeland compressor of one kind or another.
Some of the manufacturers ( maybe copeland I think) have a video of someone running the compressor dry and rolling a handfull of ball bearings into the inlet port to which the compressor spits them out the discharge side at high velocity without causing any harm to the scrolls inside the compressor.
You can be confident the scroll compressor will run for 20 years.
Well I have seen them anyway. Some of them not even serviced or looked after.
For about the first five to seven years it wears in not out becoming more efficient in the process.
Well I have seen them anyway. Some of them not even serviced or looked after.
For about the first five to seven years it wears in not out becoming more efficient in the process.
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