ᐅ Which type of geothermal energy should be used?

Hausbau83 schrieb:
The first company works with refrigerant, and the second with water.

I don’t quite understand that yet. Both offers provide direct expansion heat pumps with ground collectors. How does one of them use water? Or are you referring to Beglau’s offer, since it mentions condensation in the storage tank? How does the underfloor heating get warm then?
I have to admit I haven’t dealt much with direct expansion heat pumps so far.
In terms of content, both offers are definitely hard to compare because they provide very different services, but I assume you are aware of that. Beglau doesn’t mention the length of the required ground collectors at all (but apparently criticizes the competitor’s length, if I understood your last post correctly) and doesn’t offer installation at all.

Yes, I mean the capacitors in the storage unit. Furthermore, I am surprised by the difference between the buffer tanks; actually, the smaller one should be sufficient.

We have a heat pump as a direct expansion (DX) system with collector fields in use (although not one of the types shown here). When the heating system is properly set up, it runs smoothly. However, it requires enough refrigerant to be charged and the pressures need to be correct. Since this was not always the case for us, there were significant ground heaving and settling in the garden during the first year.

We have the same heating system installed in another residential area, and so far there have been no such issues there. The collector field was designed somewhat larger there, which apparently also benefits consumption. So, definitely do not cut corners on the collector field size. We have about 140m² (1506 square feet) of collector field for 125m² (1345 square feet) of living space.

You should be fully aware that the collector field must not be built over, no plants with root depths greater than 80cm (31 inches) may be planted, and the area is at least two weeks behind the surrounding nature in spring. This sounds manageable at first — "we just want to have grass there anyway" — but a garden tends to change gradually over time and you will face corresponding restrictions.

Additionally, we use a stratified storage tank. It works without problems during the heating season. In summer, however, you need to be careful that the set heating schedules match actual usage, since I operate with very low supply temperatures. Definitely ask how the water is heated.

Also ask about maintenance costs and intervals.

I just checked the Libind and Beglau websites.

Libind
The refrigerant flows through the collectors and also through the underfloor heating. What I haven’t found out yet is whether these are two separate circuits or just one circuit.
The domestic hot water is apparently produced using a separate domestic water pump.

The Beglau heat pump works like ours.
The refrigerant passes through the collectors. The storage tank of the heating system is heated via the reversing valve. The fresh water line runs through the storage tank and warms up as it flows through.
Here, you probably have the same problem in summer as we do. You need to heat the 600 liters (160 gallons) so that the fresh water reaches the right temperature while flowing through. This means you never have a problem with Legionella because there is no fresh water storage tank.

Just enter Libind and the product name on YouTube; there is a video available.

I also think the water storage is set a bit too high. We have 130m2 (1400 sq ft), so I believe 150m2 (1615 sq ft) should be sufficient.

We know about the garden; we only want grass there since it is located at the back of the property.

I was mainly concerned about which of the offers seems better.