Ground source heat

[suffolksmallholder]

Picture your field as a giant solar panel. In summer it will warm up and imagine the tonnage of soil which is at 12 degrees and just sitting there waiting to be transported into your house. If you have a machine (the heat pump) that can extract this heat from the water pipes buried in said field, presto you have a heat exchange. Magic eh! The best way to move heat is by water.........Hence damp clay. Dry sand just doesn't work so anyone with this type of soil should be looking at an air source.
By February you are struggling but if your pipes cover enough area you will still be able to extract some of this heat. This is a simple fact of physics.
What folk forget is this only extracts enough to heat to 55 degrees. No it's not rocket science just fact. Heat pumps are now so much more efficient they have an advantage over £'spent in this extraction process. Look at a modern freezer if you want to see how good this system is.
The big downfall is that the capital cost is big and I mean BIG but if you have faith and of course a field this is a good system.
Heavy clay is full of water.........it isn't frozen so it's above 0 degrees and possibly even + 5 in winter. You can extract this using your machinery. Your fridge does this every day of the year........
Me, I'm an insulation fan. 55 degrees is hot inside particularly when outside is at 0 degrees ie, freezing..........
SS

 

[multi power]

Picture your field as a giant solar panel. In summer it will warm up and imagine the tonnage of soil which is at 12 degrees and just sitting there waiting to be transported into your house. If you have a machine (the heat pump) that can extract this heat from the water pipes buried in said field, presto you have a heat exchange. Magic eh! The best way to move heat is by water.........Hence damp clay. Dry sand just doesn't work so anyone with this type of soil should be looking at an air source.
By February you are struggling but if your pipes cover enough area you will still be able to extract some of this heat. This is a simple fact of physics.
What folk forget is this only extracts enough to heat to 55 degrees. No it's not rocket science just fact. Heat pumps are now so much more efficient they have an advantage over £'spent in this extraction process. Look at a modern freezer if you want to see how good this system is.
The big downfall is that the capital cost is big and I mean BIG but if you have faith and of course a field this is a good system.
Heavy clay is full of water.........it isn't frozen so it's above 0 degrees and possibly even + 5 in winter. You can extract this using your machinery. Your fridge does this every day of the year........
Me, I'm an insulation fan. 55 degrees is hot inside particularly when outside is at 0 degrees ie, freezing..........
SS

yes i understand the ground is a thermal mass, bit like an old stone house

 

[scholland]

They certainly will work, if correctly designed and installed.
It's not exactly tropical here in the winter but my house will be warm all day.
They are expensive but when we bought ours there was a 40% grant scheme so it was an easy decision.

 

[Bernt]

As had been said, heat pumps if sized correctly and the heading system is designed to run at lower temps ie. Under floor heating then they work fine. Retro fitting to a existing system with rads that are designed to run at 70 degrees, they won't work without switching the immersion heater on and that is where they become expensive.

 

[Tom Sewell]

We have just got planning permission and will be building a new house soon! I initially thought about about ground source but the builder I'm using has experience with both gshp and air source recons air source far better. Underfloor on both floors will do all hot water and house heating. Wood burner in lounge and towel rails in bathrooms should do it without any radiators comfortably!!

 

[Daniel]

I have an air source heat pump running all the downstairs underfloor heating and one upstairs rad in a bedroom. It works well, the upstairs rad doesn't do muchore than take the chill off but that's good enough for me.

I wouldn't do your hot water off the main ASHP Tom, it's inefficient and will struggle to get water up to temp. I've got an ecocent which is a mini ASHP fitted to a hot water tank, it extracts warm air from the upstairs bathroom to heat the water, only uses 680 watts and means the big outdoor heat pump doesn't have to run in the summer just to heat hot water.

http://www.esavep.com/online-store/ecocent-domestic-hot-water

The air coming out of the ecocent is cold, so in the winter it can vent outside and in the summer you car direct it back into the house as aircon. Albeit aircon that only runs when you've just used some hot water!

We have 3 of these systems on three newbuilds and they all work well as long as you haven't skimped on insulation.

 

[suffolksmallholder]

Insulation is the key. Don't skimp.
Be aware of cold spots including your cold water tank (if you are not using mains pressure), cold feed pipes and toilet cisterns too, particularly if these are hidden. Lagging these is paramount. Condensation will occur in any place where there is a heat difference and this may happen for years unseen and the resulting problems could be costly to repair.
SS

 

[tayside renewables]

If anyone has any questions on Ground Source please feel free to fire away, we are VIP installers for NIBE and have installed 8kW to 80kW with bore hole and ground loop projects

 

[Pasty]

I've been looking at this. 3 bed detatched barn conversion. Insulation is OK but not brilliant. I own the field in front which is flat, clay and about 5 acres. Have a largish barn across the yard which is south facing and probably 18 x 5m or so of roof each side with a decent slope and no shade.

Current set up in the house is full UFH which used to run off a combi boiler. Later we added an Esse W23 wood stove connected to a 200l Gledhill Torrent heat store. The boiler now runs through a coil in the tank to keep it up to temp when the stove is off / low and DHW comes from a heat exchanger in the tank. It kind of works but to be honest not very well. The cooling water is always pulling down the stove so it rarely burns properly (I think a Laddomat would sort this) and all summer we are burning gas to keep a huge tank warm just for DHW. Which is silly. I also have concerns that the heat store is way too small for the house as the boiler runs pretty much all the time in the winter. Net effect is that the Esse has had no real impact on our gas useage.

So, my thinking is PV on the roof of the shed connected to the house as well. Immursun thing and maybe also solar water on the roof of the house for good weather DHW. Ground source pump looks good. Can these be connected to a heat store or is that not how it works? If not, how do you get back up for it in very cold weather? Does it just connect straight to the UFH manifold like a combi? Also, I'm looking at figures of £15k install and £30k RHI payments in the first 7 years! Is that correct?

I basically want to get a fully integrated system which means no energy needs to be bought in.

 

[ashelton]

Take a look at our new CT150 installing GHSP pipe work.

 

[Exfarmer]

There certainly is heat in the ground you just have to go far enough down to find it.
The deeper the better, even in west Wales. However if it is rock 6 inches down you can forget conventional ground source. However as someone else pointed out you may be able to go for a deep bore system if the ground is suitable..
I am perplexed at air source, many sing its praises , but my plant, 6Kw, to give 18Kw of heating very quickly freezes up in the Autumn and needs to run in reverse cycle to defrost. When it is doing this the efficency very rapidly drops and I am certain soon gets under a 1:1 return.
works very well in summer though. I have given up trying to run it over winter.
If someone knows a model that will work all year round I would purchase it.

 

[Grassman]

I will be fitting a ground source system in the spring. Just building a new bungalow with underfloor heating.
A neighbour had it a couple of years ago and is very happy with it. He went through last winter with no other heating and hot water is done by it as well.

 

[Cowcalf]

as I understand the best ground for GSH is damp ground with the water moving slowly across the installed pipe work so it has chance to exchange the heat

 

[Grassman]

as I understand the best ground for GSH is damp ground with the water moving slowly across the installed pipe work so it has chance to exchange the heat

Mine is heavy clay which I was told was good.

 

[Farmer_Joe]

i got one when there was a grant on, yuo can use rads as i have both up and down stairs with complete sucess. you sinply have to over spec the sizes required by 20% if i remeber correctly.

Insulation is a big factor but if its a new build or conversion the current regs are fine.

Mine does both hot water and heating on a converted barn, its 3 bed and the heating is literally on 24/7 365 days a year elec aprox 100 per month (Average) inc some farm use i.e welding etc...

As above installation is key, you need plenty of ground loop to recoup the losses or it wont work and installed preferably in boggy land that will conduct properly,

plently of bell ends that are experts installing crap systems with substandard loops etc that will work crap.

Company that supplied my boiler were bought up by a bigger firm but i installed the boiler and the loop so i knew it was done correctly having worked with someone who fitted them commercially prior.

 

[ski]

Take a look at our new CT150 installing GHSP pipe work.View attachment 242952

How does it cope on very stony ground?

 

[ashelton]

Yes not to bad, been in some very awfull digging conditions and coped very well.

 

[Grassman]

Yes not to bad, been in some very awfull digging conditions and coped very well.

Is it any good in wet yellow clay @ashelton.
Your location isn't showing.

 

[Stuckingeneva]

Im in the process of pricing up ground source for a new build, but i'm sceptical. I Like hot baths, can anyone confirm that there will be enough hot water for this?

 

[Grassman]

Im in the process of pricing up ground source for a new build, but i'm sceptical. I Like hot baths, can anyone confirm that there will be enough hot water for this?

My neighbour said it did all his hot water all winter. They do have an immersion heater connected to the mains to top up if necessary. His electric bill was very low.