Hunter2605
2022-04-15 17:18:53
- #1
Beforehand, neither you nor the heating engineer need to worry about the model. It can basically only go wrong. Determine the heating load, choose the appropriate model. Not bigger, not even if it can modulate wildly.
A 9 kW heat pump is definitely way too big for a new building. That is the capacity my uninsulated old building with 260 sqm requires. For you, I estimate 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. In addition, it needs expensive additional hardware like buffer tanks, valves, differential pressure valves, which could be avoided if the heat pump is chosen appropriately. Oh - of course, a 4 kW heat pump is also much cheaper than a 9 kW one. So this sizing actually means a difference of many thousands of euros!
I don’t know exactly where they are required. I equipped both a new building in 2016 and an old building in 2020 without these things. But apparently, they are required somewhere. Those who calculate the heating load can also apply for exemption.
Anyway, you should definitely leave them out. They cost a lot of money. The electrician has to pull many more cables alone. Then they consume electricity permanently and THEN they also ruin the clean control of the underfloor heating. All this WITHOUT the slightest added benefit.
So get informed and ditch those things, that is technology from 40 years ago, when there were no heat pumps yet.
We are building a detached single-family house in brick construction with external thermal insulation composite system (ETICS). Of course, we comply with the energy-saving ordinance, but we do not have a specific KfW standard. Do you really only have 3.5 to 4 kW for 170 sqm (of which 152 sqm are heated)? I would have expected more.
Then the LWDV from Alpha Innotec really seems oversized. What do you think about the LWAV (also from Alpha Innotec) as an alternative? They come in two versions. The smaller one has 6 kW.