Expand ground source heat pump to heat a small indoor pool

The fact that the manufacturer does not provide any precise information about the filter size, pump, etc. already speaks volumes. There are also plenty of other manufacturers. Low purchase costs usually mean higher maintenance costs and increased servicing/operational effort.

If I were you, I wouldn't touch the heating circuit and would make a drilling outside for the pool and set up a proper inverter heat pump for the pool there. So heat pump outside, piping inside. Then you are independent and (very likely) even cheaper.

If I were you, I wouldn’t touch the heating circuit and would make a borehole to the outside for the pool and set up a proper inverter heat pump for the pool there. So, heat pump outside, piping inside. Then you are independent and (very likely) even cheaper.

Thanks for the answer.

Disadvantage:
- Additional costs for a second heat pump (4 kW like the supplied electric heater? 400-600 €)
- Additional costs for drilling through the wall
- Lower efficiency of the pool heat pump (air-water) compared to the house heat pump (brine-water/geothermal)

Advantage:
- No intervention in the configured heating circuit

Am I missing something?

You mean the advantages outweigh not only regarding the cleanliness of the solution (independent heating systems) but also economically?

Thank you for the answer.

Disadvantage:
- Additional cost for a second heat pump (4 kW like the supplied electric heater? 400-600 €)
- Additional cost for drilling through the wall
- Lower efficiency of the pool heat pump (air-water) compared to the house heat pump (brine-water/geothermal)

Advantage:
- No intervention in the configured heating circuit

Am I overlooking something?

You mean the advantages outweigh not only from the cleanliness of the solution (independent heating systems) but also economically?

Have you already obtained an offer from the heating engineer to connect the geothermal heat pump circuit with the pool system? Normally, a heat pump is designed according to the heating load calculation to supply the house as efficiently as possible.

Your indoor pool is a considerable additional load that (probably) your heating system is not designed for. Or did you plan from the beginning to connect a pool and dimension the system larger accordingly?

Have you already obtained an offer from the heating engineer to connect the geothermal heat pump circuit with the pool system? Normally, a heat pump is designed based on heating load calculation to supply the house as efficiently as possible.

Your indoor pool is a significant additional load, for which (probably) your heating system is not designed. Or did you plan from the beginning to connect a pool there and dimension it larger right away?

The pool was not planned from the beginning.

My considerations were – as written –:
- It is not an outdoor pool that cools down significantly at night.
- Initial warming of the pool could take place in summer.
- The pool’s heat is not lost either but stays in the house.
- If in the deepest winter the capacity is no longer sufficient to heat both the house and the pool at the same time, that would not be a problem, then the pool would simply not be heated during that time.

My energy consultant contacted her MEP planner and he writes:
“It is basically technically possible to connect the pool to the heat pump, how exactly this behaves with the Ecoforest would have to be assessed by an installer, as he is not very familiar with the device. He recommends installing a priority control so that only the excess energy is directed to the pool and the heat demand for the building is covered first. It should work that way.”

If the heating capacity is not sufficient, one can always consider an additional heat pump.

The pool was not planned from the start. My considerations were – as written –: - It is not an outdoor pool that cools down significantly at night. - The initial heating of the pool could take place in the summer. - The heat of the pool is not lost, but remains in the house. - If in the deep winter the capacity is no longer sufficient for house heating and pool heating at the same time, that would not be a problem, then the pool simply would not be heated for a while. My energy consultant contacted her TGA planner and he writes: "It is basically technically possible to connect the pool to the heat pump, how exactly it behaves with the Ecoforest would have to be assessed by an installer, as he does not know the device that well. He recommends installing a priority switch so that only the excess energy is fed into the pool and initially the heat demand for the building is met. That should work." If the heating capacity is not sufficient, one can always consider an additional heat pump.

I am quite sure that you will do better and cheaper with a separate inverter heat pump for about 1000 EUR and a small external borehole than if you have an installer modify your existing house heating system. I do not know what a priority switch costs, but it sounds expensive :-)