ᐅ Cooling in summer with an air-to-water heat pump, underfloor heating, and/or a ventilation system?

Hello,

currently, the installation of an air-to-water heat pump, underfloor heating, and a ventilation system from PLUGGIT is planned for our single-family home.

Now that temperatures are pleasantly rising, it is already getting quite warm in our current older building. Of course, the single-family house will (hopefully) be better insulated and proper shading will be provided, but due to the large glass surfaces, it could still become very warm in the summer.

We are now considering whether we should also provide air conditioning; there seem to be several options:

a) Installation of a different reversible air-to-water heat pump; cooling would then be provided via the underfloor heating system. It is not entirely clear to me how much cooling can be achieved this way, and a condensation sensor is probably mandatory.
b) Installation of the ventilation system with a ground source heat pump to supply cooler fresh air.
c) Adding a dedicated air conditioning unit before the ventilation system?
d) Installation of a “real” air conditioning system along with fan coil units.

Option d) is excluded due to cost; do options a), b), or c) offer anything useful and can be added for a “small” additional cost? a) and b) appear to be the most practical...

For b), PLUGGIT also offers appropriate solutions (products: SWT180 and GTC); not sure about cost/efficiency.

For a), Stiebel probably has corresponding options; also unknown cost/efficiency. The main concern here is that it might only create a “cold spot” on the floor but not actually cool the room in general.

Any opinions?

Thanks.

Passive cooling works and has low operating costs. However, it is not an air conditioning system. A cold air layer near the floor cannot be denied, but ventilation creates convection in the room anyway. I experienced this at friends’ houses, and it works.
A ground heat exchanger for a central ventilation system is also a good option.

Each of these options costs from €3,000 (approx. $3,200) upwards.

For b), be careful about what kind of solution it is. There are different variations. One uses a real brine heat exchanger, while the other only channels the supply air through a long underground duct, which can lead to microbial growth due to condensation.
Keep in mind to decide on this early so the brine pipe can be installed while the excavation is still open – this saves earthworks.
If at all, I would opt for the brine solution.
However, I haven’t completely made up my mind yet.

It seems we at least agree that the options lean more towards a) active cooling via a reversible air-to-water heat pump combined with underfloor heating, or b) passive cooling using a ground heat exchanger through the ventilation system; options c) or d) are probably less suitable.

Could option a) also be equipped with a ground heat exchanger instead of active cooling?
Presumably not with a pure air-to-water heat pump but only with a brine system, correct?

The question is which of the two is better, or whether it makes sense to combine both systems.

AnNaHF79 schrieb:

Could you a) also equip it with a ground heat exchanger instead of active cooling?
Probably not with a pure air-to-water heat pump, but only with a brine system, right?

Good question, I’m not sure. With a brine-to-water heat pump, the ground heat exchanger is included by design. Accordingly, the cooling function is also more efficient compared to an air-to-water heat pump. Whether that difference is noticeable, I don’t know. I’m currently considering whether to skip the cooling option on the air-to-water heat pump and instead invest the cost savings in the brine heat exchanger for the balanced ventilation system. The advantage of the balanced ventilation solution is not only cooling the incoming air in summer but also pre-conditioning that air in winter, which can make a preheating coil unnecessary.

Maybe someone with experience can share which solution provides better cooling when choosing between an air-to-water heat pump with cooling function or a balanced ventilation system with a ground heat exchanger.

Check the cooling capacity of both systems.

I have already opted out of the preheating coil for the mechanical ventilation with heat recovery, as according to experience reports, it rarely activates anyway, and with enthalpy control, the system apparently continues to run at even lower temperatures. Additionally, it is available as an accessory and can be easily retrofitted.