As regards the ground source heat pump, ours is actually not a grid layout under the lawn, but four deep (100m +) drilled holes to do the job of collecting the heat. It was very expensive, but we managed to get it done just in time to have the government subsidy, approx 50% but repaid quarterly over seven years. We also needed to get cavities filled and have a bit of outside insulation on a solid brick wall.
It is very good. Our regular usage is well below the requirements, ie it is supposed to be able to maintain the house at 21C in down to -4C weather: we set the temperature at about 17.5 unless we have guests. And we often get an efficiency of 8, instead of 4. Admittedly I am still convinced that it is all done by Magic, but my husband (the physicist) understands how it works, so fair enough.
Neighbours who have a very large but brand new and well insulated building have an air source heat pump and no complaints.
no subject
It is very good. Our regular usage is well below the requirements, ie it is supposed to be able to maintain the house at 21C in down to -4C weather: we set the temperature at about 17.5 unless we have guests. And we often get an efficiency of 8, instead of 4. Admittedly I am still convinced that it is all done by Magic, but my husband (the physicist) understands how it works, so fair enough.
Neighbours who have a very large but brand new and well insulated building have an air source heat pump and no complaints.