Air-to-air heat pump vs air-to-water heat pump vs ring trench collector - differences

Well, never say never. Sometimes putting a foundation for a wall, a pergola, or a sun sail in the ground will be difficult if there are pipes everywhere.

Never say never. Setting a foundation for a wall, a pergola, or a sun sail into the ground will be difficult if there are pipes everywhere.

The pipes are actually at least 1.5 meters deep... I can't think of anything that would be concreted in that deep. And building above it is not a problem.

A large pool would probably be a problem..

We recently installed a ground collector (four circuits of 300m DA32 each). Here are my notes/tips briefly:
- Check the Water Resources Act to see if a permit is required. Usually, only a notification obligation exists.
- Are there specific regulations in your federal state regarding the distance (neighboring property)?
- Is the soil suitable (keyword: thermal conductivity of the rock)?
- The energy in these shallow circuits is drawn from solar or precipitation heat. Does the soil receive enough sunlight and sufficient infiltration (later not to be built over, not sealed)?
- There are also other types such as trench collectors, geothermal baskets, energy columns ...
- Material: especially stress crack resistant PE 100-RC (lifespan decreases above 25°C, if, for example, regeneration with solar heat is planned, then switch to PE-X)
- Regarding the wall thickness of the pipes, there is a bit of a dilemma between thin (low thermal resistance, high bending radius) and thick (durability and protection).
- I recommend welding with socket fittings. For this, the pipe must correspond, for example, to class SDR11.
- With multiple circuits, one should try to install approximately the same length (maximum deviation 10%).
- There are multi-utility house entries that already allow for two geothermal pipes.
- Pay attention to laying distance and depth. For example, distance to wastewater pipes, foundations, ...
- Brine fluid: The ready-made mix down to -40°C is relatively expensive. It is best to mix yourself for a lower freezing point. We use -15°C because the heat pump switches off anyway at -5°C.

Good luck!

Yesterday, in addition to the currently favored air-to-water heat pump or gas heating, I also came across the ring trench collector heat pump. The following questions come to mind:
Main concern: - I imagine that after renting an excavator, the installation is doable as a DIY project, but on the strip where the ring trench collector is laid, due to frost, no plants will grow later. How far does this cold radiate, i.e., how wide is the exclusion zone around the ring trench collector for plants, trees, bushes, etc.?
Secondary issue: - I actually have to always hire a paid expert beforehand who assesses whether my soil is suitable, right?

Another question, because it is also included here by the original poster: do you actually install an air-to-water heat pump and then also a controlled residential ventilation system with heat recovery, or is the controlled residential ventilation only used with an LL heat pump?

Do you usually install an air-to-water heat pump and then also a controlled residential ventilation system with heat recovery, or is the controlled residential ventilation system actually only used with ground source heat pumps?

A controlled residential ventilation system can always be installed - even with a gas heating system or night storage heaters. You must distinguish between ventilation (which is like opening a window) and heating.

A controlled residential ventilation system can always be installed - even with a gas heating system or night storage heaters. You have to distinguish between ventilation (which is like opening a window) and heating.

Yes, okay, thanks! I only thought of that because with an LL heat pump, ventilation is also the heating of the rooms. But that’s probably true.