Hot water only with heat pump?

I need some help from an expert: We are building a single-family house, building application 2015, 115 sqm living space, no basement, 7.5 sqm utility room. Now we are facing the question of heating investment: Either a gas condensing boiler running on liquid gas (natural gas is not available), however the roof orientation is not optimal for solar thermal. Or an air-to-water heat pump?? The planner recommended a compact unit from Fiesmann;). A heating specialist, however, told me that the water storage would not be sufficient; he would definitely place a storage tank next to it. Apart from the investment costs, we also want to be able to use the utility room for other purposes and not completely fill it with technology. What would you recommend? Thank you very much for your answers!

I need some help from an expert: We are building a single-family house, building application 2015, 115 sqm living space, no basement, 7.5 sqm utility room. Now we are facing the question of heating investment: Either gas condensing boiler with liquefied gas (no natural gas available), however the roof orientation is not optimal for solar thermal. Or an air-to-water heat pump?? Here the planner recommended a compact unit from Fiesmann ;). However, a heating expert told me that the water tank would not be sufficient, he would definitely place an additional tank next to it. Apart from the investment costs, we also want to be able to use the utility room for other purposes and not completely fill it with technology. What would you recommend? Thank you very much for your answers!

Hi, we have about 110 sqm living space, no basement, KFW70.

Our utility room has 4.96 sqm and despite all the technology (also a Pluggit Avent 310 Controlled Residential Ventilation with heat recovery is installed, which also takes up space) it is still very usable if you come up with one or another clever solution.

Gas condensing boiler GB-172 from Buderus as heating.

Solar thermal collector facing east. That is not optimal, but it only costs 5-8% compared to south orientation. Don’t expect too much from the solar thermal. The hot water costs are not that high anyway, what the solar thermal saves usually is not recovered (investment, interest, repayment).

We have a hot water tank with 300 l volume. Layered storage tank, because of the solar thermal system. Usable volume in winter is about 150 l. The rest below for the solar thermal system is cold... (it’s not running).
Now it depends on what warm water volume the offered Viessmann air-to-water heat pump offers. For a full bath, count on 100-150 l easily, that is gone quickly. I usually run the hot water at 45 degrees. If I take a bath (big tub) I increase it once to 60 degrees because otherwise I run out of hot water while bathing. Thus, the advice of your expert to install an additional tank could definitely be absolutely reasonable.

Best regards
Thorsten

Hello Thorsten,

Are you otherwise satisfied with the GB 172? Doesn’t it have an integrated stratified storage tank? Your ST is only on the east side, meaning you charge your storage with the morning sun??

Thanks and regards

Hi Bortel,

I am very satisfied with the GB-172. The price/performance ratio is excellent.

The storage is separate. GB-172 is small, wall-mounted.

The east side: Charges from the morning until the afternoon.

Many best regards!
Thorsten

Thank you