KfW55: Gas or air-water heat pump with/without photovoltaics

For the THZ304, a sound power level of 56dB is specified. No idea if that's a lot or not.

56 dB is somewhat louder than a normal conversation.

Up to 150 sqm, the THZ304 should be sufficient. As for noise, we were told that with an air-water heat pump, the utility room is insulated additionally.

For the THZ304, a sound power level of 56dB is specified. No idea if that's a lot or not.

Then the limit to the 404 was really 160 sqm, for us with about 165 sqm it has to be that one. Then the additional cost to the 504 is not that much. It is still a bit quieter and, with inverter technology, also more efficient. According to the datasheet I saw on the Tecalor page, the 304 eco has 60db, the 504 50db, which is supposedly perceived as roughly half as loud.

Then the limit to the 404 was really 160sqm, with us at about 165sqm it must be that one. The extra cost for the 504 is then not that big. It is a bit quieter and also more efficient with inverter technology. According to the datasheet I saw on the Tecalor site, the 304 eco is 60dB, the 504 is 50dB, which is roughly perceived as half as loud.

I looked at the THZ304SOL, and it is 58dB there. What is the main difference between SOL and ECO anyway? Only the cooling function?

And the difference between 504 and 304? Even better efficiency (A+++) and with ISG/ISG Plus own solar power as far as I can see? But you can also connect the THZ304 to photovoltaics, right?

And price-wise?

The SOL can probably be supplemented with ST. The 504 is supposed to be more efficient and have a higher annual performance factor. Unfortunately, there aren't many real consumption data. In the heat pump consumption database, there is only one entry, but with a performance factor of 4.5 instead of around 3.5 like the 304. However, this is not really meaningful. The difference between 304/404/504 from memory is: 11500/13000/17000, whereby the 504 is probably subsidized with 1500€ by BAFA (see thread BAFA Förderung). The step up from the 304 is already so big that I probably wouldn't consider it.

The SOL can probably be supplemented with ST. The 504 is supposed to be more efficient and have a higher annual performance factor. Unfortunately, there aren't many real consumption data. In the heat pump consumption database, there is only one entry, but with a performance factor of 4.5 instead of rather 3.5 like the 304. However, this is not really meaningful. The difference between 304/404/504 from memory is: 11500/13000/17000, whereby the 504 is probably subsidized with 1500€ by BAFA (see thread BAFA funding). The step from the 304 is already so big that I probably wouldn't consider it.

So, 504 is oversized for 150 sqm and KfW55? Thanks for the link about BAFA. The list also includes the 304. But do I understand correctly that the air-water heat pumps are only subsidized in combination with ST?

I wanted to do without ST. If anything, then photovoltaics.

Hey,

we have the 304 eco in the utility room. To prevent the sound from spreading too much through the house, the screed under the system is separated from the rest and the tiles are also not directly connected to the other tiles in the room. The system hums constantly, but it is only really loud when it is preparing hot water (for us in the evening around 6:30 pm and in the morning around 7 am).

We have a completely normal interior door in the utility room and nothing extra insulated. When the door is closed, you can still slightly hear the system humming in the hallway, but you can't hear it at all in the adjacent rooms. When the washing machine spins, that is significantly louder! Upstairs in the bedrooms, you cannot hear the system at all.

But it's definitely always a matter of sensitivity and getting used to it. The system doesn't bother us at all; even though I am a very light sleeper, I don't notice it.