Which air-to-water heat pump is suitable for new construction?

Hello everyone,

we will build a single-family house without a basement (ground floor + attic) with about 170 sqm and are looking for a good air-to-water heat pump for this. The device should be inverter-controlled as well as a monoblock system for outdoor installation. The device should be as efficient as possible but also as quiet as possible.
Our developer mostly installs heat pumps from the company Alpha Innotec. Here, either the model LWDV or LWAV+ would fit the above criteria.

What do you think of Alpha Innotec and the two mentioned models? Are there any experiences?

I would also be grateful for recommendations of other systems and manufacturers.

Best regards
Felix

I would suggest the Panasonic Aquarea as a great alternative from my own experience. It is also cheaper. The question is whether your builder or their heating engineer is familiar with it.

P.S. I have installed two of the Panasonic myself.

If the pumps have not been on the market for longer than 3 years and ideally still use R290 as a refrigerant, they can't be bad. More important than the brand is to ensure that the pump does not have more capacity than the house heating load. The latter must be provided to you calculated room by room (this is needed anyway for the design of the underfloor heating; if there is none, it's botched). The pump should then not be larger than the cumulative heating load of all rooms. Without allowances for hot water, dog, or grandma. Also, you want an exemption from the EER (this is applied for by the planner who also does the calculations) and NO heating buffer (not to be confused with the domestic hot water tank). This now only as key points. Why all this is so, you can read in every second heat pump thread here.

If the pumps have not been on the market for more than 3 years and ideally still use R290 as a refrigerant, they cannot be bad.
More important than the brand is to ensure that the pump does not have more capacity than the house heating load. The latter must be presented to you calculated room by room (this is needed anyway for the design of the underfloor heating; if there isn’t one, it’s botched). The pump should then not be larger than the cumulative heating load of all rooms. Without allowances for hot water, dog, or grandma.
Also, you want an exemption from the EER (this is applied for by the planner who also does the calculations) and NO heating buffer (not to be confused with the domestic hot water tank).
Just as keywords for now. Why all this is the case you can read here in every second heat pump thread.

Thank you very much for your helpful answer. However, I have a few questions for clarification:

> The LWDV as an inverter-controlled air heat pump has a power range from 3 to 9 kW.
At Alpha Innotec it says: "The devices are recommended for the following overall building power demand: LWDV 91-1/3 = 6-11kW." To my knowledge, the LWDV is not available in another size/design. At the same time, I am tied to Alpha Innotec through my builder. Could it be, despite modulation, that the LWDV is oversized for our new building (single-family house with approx. 170 sqm without basement)? Unfortunately, I do not yet know the exact heating load.

> What is the deal with the EER and why is an exemption needed? Does it have to do with subsidies? If so, we are building a new building. As it stands, there are currently no subsidies anyway.

A thousand thanks for your support!

I operate the LWDV with 200m2 of living space and a heating load of 5-6kW. If you properly design the underfloor heating, install a wall heating in the bathroom, deactivate the individual room controllers, close the bypass valve, and perform a hydraulic balancing along with a low heating curve yourself, then the pump can definitely be controlled and has an average running time of over 5 hours here with me. In winter, the pump ran continuously for more than four weeks. However, the pump is still tended to be slightly oversized. I only chose it back then because of the >10k BAFA subsidy (only this manufacturer was possible). If you choose the standard design and settings of the heating installer and do not want to take care of it yourself, it’s better to choose a weaker model. There is a risk that the pump will not dissipate its heat properly and will constantly switch on and off.

Unfortunately, I do not yet know the exact heating load.

Before that, neither you nor the heating installer need to worry about the model. It can basically only go wrong. Determine the heating load, choose the appropriate model. Not larger, even if it can modulate wildly.

A 9 kW heat pump is definitely much too large for a new building. That is the power my uninsulated old building with 260 sqm requires. I estimate you need about 3.5-4 kW. And unlike oil or gas, an oversized heat pump is really bad. It is much less efficient and breaks down much earlier than necessary. Furthermore, it requires expensive additional hardware like buffers, valves, bypass valves, which could be avoided if you choose the heat pump appropriately. Oh yes - of course a 4 kW heat pump is also much cheaper than a 9 kW one. So this sizing actually involves a difference of many thousands of euros!

> what is EER about and why is an exemption needed?

I don't know exactly where they are mandatory. I have equipped both a new building in 2016 and an old building in 2020 without these things. But apparently, they are mandatory somewhere. Those who calculate the heating load can also apply for the exemption.

Anyway, you should definitely leave them out. They cost a lot of money. Just the electrician has to pull many more cables. Then they continuously consume electricity and THEN they also ruin the clean regulation of the underfloor heating. All this WITHOUT the slightest additional benefit. So do your research and get rid of these things, that is technology from 40 years ago, back when heat pumps did not yet exist.