Heat Pump.

Gideon: 
……  it's about heat pumps, isn't it? 

So, back to the topic.

I first looked at geothermal heating 15 years ago. The conclusion is that it would not work for my building unless (a) I insulated it completely and (b) I installed completely new heating circuits. I have been through that in previous posts.

I just looked up the current situation, since I'll probably need a new heater in at most 5 years. 

The typical installation has the circuit to a depth of about 100m. Then there are heat exchangers in the house. However, typical temperatures are 35°C and my current system needs 50° or so. Underfloor heating is recommended. That would be impractical for me to install.

Installation cost is said to be €17K-€19K, up to the exchanger I take it. That is less than it was. I read that maintenance costs are negligible, but they certainly weren't 15 years ago, in particular concerning keeping the probe in working condition. It is going to depend on the local subsurface morphology and dynamics.

The energy is said to come about ¼ from the electricity needed to operate the exchanger and pump inside the house, and ¾ from the earth warmth.  I don't know how accurate that is.

There is another system, which I didn't know about 15 years ago and would be impractical for me, because I don't have a field. Apparently you can install flat collectors some 1-2m below the surface and they pick up the solar heating of the surface layer. But you need a lot of land……

Gideon: 
……  it's about heat pumps, isn't it? 

So, back to the topic.

I first looked at geothermal heating 15 years ago. The conclusion is that it would not work for my building unless (a) I insulated it completely and (b) I installed completely new heating circuits. I have been through that in previous posts.

I just looked up the current situation, since I'll probably need a new heater in at most 5 years. 

The typical installation has the circuit to a depth of about 100m. Then there are heat exchangers in the house. However, typical temperatures are 35°C and my current system needs 50° or so. Underfloor heating is recommended. That would be impractical for me to install.

Installation cost is said to be €17K-€19K, up to the exchanger I take it. That is less than it was. I read that maintenance costs are negligible, but they certainly weren't 15 years ago, in particular concerning keeping the probe in working condition. It is going to depend on the local subsurface morphology and dynamics.

The energy is said to come about ¼ from the electricity needed to operate the exchanger and pump inside the house, and ¾ from the earth warmth.  I don't know how accurate that is.

There is another system, which I didn't know about 15 years ago and would be impractical for me, because I don't have a field. Apparently you can install flat collectors some 1-2m below the surface and they pick up the solar heating of the surface layer. But you need a lot of land……