Ground source v air source

[Headless chicken]

For a new build house. Unsure which to go for. Air source is cheaper but not sure I’m too keen on the unit on the side of the house. What’s others experience?

 

[davidroberts30]

My brother got GS And parents got AS
Both seem to work ok
Dont forget the other renewable energy to keep the running costs down

 

[deleted user 837354]

In laws have air source. Runs a lot and can be noisy unless you site it away from your house. You don't need it on the side of your house.

Their electricity bill to run it is not cheap.

 

[dazza b]

Air source unit closer to house is cheapest option soon as start having to put district pipe and it’s expensive

 

[Courier]

Do not skimp on the insulation then either will do the job - AS simpler, cheaper, quicker to install but maybe fractionally more expensive to run if the insulation is not up to par...

 

[steveR]

For a new build house. Unsure which to go for. Air source is cheaper but not sure I’m too keen on the unit on the side of the house. What’s others experience?

Have you the land available to put in a GSHP ground loop? Not one of the "back garden" type loops either.

If you have, then that will be the better long term option everytime, other than as you rightly say, a higher initial capital cost.

You can easily fit an ASHP eleswhere, on a garage wall or even a dedicated house for it.

 

[steveR]

In laws have air source. Runs a lot and can be noisy unless you site it away from your house. You don't need it on the side of your house.

Their electricity bill to run it is not cheap.

Hearing that from several with ASHP, one with a new build and modern insulation... Easy to put in by a jobbing plumber and simple install.

I did see one ASHP put on the inside of a building to stop issues with snow and ice blocking the entry vents in bad weather, but whether it stops the system having to de-ice itself...?

 

[Headless chicken]

My brother got GS And parents got AS
Both seem to work ok
Dont forget the other renewable energy to keep the running costs down

We’ve a wind turbine onsite that we part own but have a cap on total units that we would exceed anyway so would be back to grid. If my understanding is correct GS is cheaper to run?

Do not skimp on the insulation then either will do the job - AS simpler, cheaper, quicker to install but maybe fractionally more expensive to run if the insulation is not up to par...

Builders are doing the outside insulation and putting timber frame up so that leaves less room for the farmer in me to come

Have you the land available to put in a GSHP ground loop? Not one of the "back garden" type loops either.

If you have, then that will be the better long term option everytime, other than as you rightly say, a higher initial capital cost.

You can easily fit an ASHP eleswhere, on a garage wall or even a dedicated house for it.

Space to run loops is no problem. Am I right in thinking there would be nothing noticeable on the exterior of the house with GS?

 

[___\0/___]

We’ve a wind turbine onsite that we part own but have a cap on total units that we would exceed anyway so would be back to grid. If my understanding is correct GS is cheaper to run?

Builders are doing the outside insulation and putting timber frame up so that leaves less room for the farmer in me to come

Space to run loops is no problem. Am I right in thinking there would be nothing noticeable on the exterior of the house with GS?

Nothing at all on the outside, just a hot water tank, control unit/pump in the house somewhere. Great system

 

[Wurzeetoo]

I had air source in my old house when I bought it. I wouldn’t ever either install it or buy a house with it again. Expensive to run and very temperamental, if I had kept the house I would have ripped it out and put an oil fired boiler in

 

[steveR]

We’ve a wind turbine onsite that we part own but have a cap on total units that we would exceed anyway so would be back to grid. If my understanding is correct GS is cheaper to run?

Builders are doing the outside insulation and putting timber frame up so that leaves less room for the farmer in me to come

Space to run loops is no problem. Am I right in thinking there would be nothing noticeable on the exterior of the house with GS?

Nothing needs to be on show at all. Drop your loop in at about 1.5m+ and carry on farming on top.... The Heat Pump and tanks can go inside the house, or ideally, in it's own little house/shed. Things can and do go wrong, and it is wise to have a separate location not in the house, and certainly not upstairs in teh house....

 

[Headless chicken]

Nothing needs to be on show at all. Drop your loop in at about 1.5m+ and carry on farming on top.... The Heat Pump and tanks can go inside the house, or ideally, in it's own little house/shed. Things can and do go wrong, and it is wise to have a separate location not in the house, and certainly not upstairs in teh house....

we have a “garden store” attached to the house with a set of big double doors which I hope will be sufficient to house it. It was intended for a ride on mower but I’ll be going robotic after seeing dads working anyway. Suspect this thread has kindly answered my questions.

 

[steveR]

we have a “garden store” attached to the house with a set of big double doors which I hope will be sufficient to house it. It was intended for a ride on mower but I’ll be going robotic after seeing dads working anyway. Suspect this thread has kindly answered my questions.

Perfick!

Hope it all goes well for you. Just make sure the installers really know their stuff. I know a guy near Mach with a fairly new GSHP setup who is pleased with it...

 

[Mur Huwcun]

we have a “garden store” attached to the house with a set of big double doors which I hope will be sufficient to house it. It was intended for a ride on mower but I’ll be going robotic after seeing dads working anyway. Suspect this thread has kindly answered my questions.

That sounds ideal, I built a small lean to on gable end if house and wrapped the whole shed with 100mm kingspan. My water pump and heat pump with allexpansion vessels live there with hot water tank upstairs next to bathrooms and above kitchen sink. We also have a buffer tank in the utility room. Really glad this back end that the HP is in its own shed as with all this rain the water table has been messed up and water has been coming up the ducts from the ground where the loops enter. It’s never happened before but would of been a disaster in an utility room!!!

 

[Rattie]

Latest ASHP systems are almost silent. I fitted an 11kw Mitsubishi pump with 300L solar thermal ready cylinder along with all the pumps for underfloor heating, instant hot water (some long runs, would have taken 30-40 seconds to draw hot water in distant bathroons) etc for under £6k. Pays rhi of just over 10k, so rhi also payed for UFH work and givlon screed over 140m².

The equivalent GSHP was best quote at £19k if I payed for and installed the 400m of pipe in the field next to the house, (23k total approx) for an rhi payment of £15k, plus cost of UFH and Screed at a cost of £4000 fitted.

ASHP doing just over 3 COP after a year, with no issues so far, I think GSHP would need to have done well over 5 COP to compare, which was highly unlikely. I figured £12k would pay for a lot of running costs over 20 odd years.

 

[MikeNeaverson]

I got numerous quotes and cheapest was £7k for AS vs £16k for groundsource. The RHI pays for the difference over 7 years so it’s a capital issue really. Efficiencies roughly 3:1 for AS and 4:1 for GS. Sounds a big difference but for my house will only be a saving roughly £150/year in electric bill for an additional outlay of £9k.

 

[Lakesdigger]

One thing they don't tell you about ground source is over time it becomes less efficient. Basically it cools the ground around the buried pipes and over a number of years the temp difference between flow and return will become less. This is more common where multiple pipe runs are buried closer together in a smaller area of land. It may not make a huge efficiency difference but it will narrow the running cost gap between gs and as (may even level it out)

 

[S J H]

I had air source in my old house when I bought it. I wouldn’t ever either install it or buy a house with it again. Expensive to run and very temperamental, if I had kept the house I would have ripped it out and put an oil fired boiler in

That’s my thoughts, I’d still have air source on a new build just to comply with the energy rubbish, but once ours packs up, I’ll change it for oil.

 

[S J H]

One thing they don't tell you about ground source is over time it becomes less efficient. Basically it cools the ground around the buried pipes and over a number of years the temp difference between flow and return will become less. This is more common where multiple pipe runs are buried closer together in a smaller area of land. It may not make a huge efficiency difference but it will narrow the running cost gap between gs and as (may even level it out)

I was told aswell, that the clay shrinks around the pipe so will have less contact.

 

[Lakesdigger]

I was told aswell, that the clay shrinks around the pipe so will have less contact.

Its not ground shrinkage that i was thinking was the main issue but the fact there is no heat source at the depth which the pipe is installed. Are we honestly supposed to believe a good summer will heat the ground that far down.
Also ideally wants to be in ground which is wet or holds water for good contact with the pipe. If its gravelly or sandy and free draining probs not worth the expense. Ultimately with a lot of the renewables is only the rhi payments which make it worthwhile. Once these run out what's your plan?