ᐅ Heating via ventilation system with heat pump

Created on: 9 Jun 2017 22:11
T
Tobibi
Hello,

We are interested in a house that is currently for sale and are already in negotiations. We have now learned that there was a misunderstanding regarding the heating system. It is heated with a heat pump; until now, we thought there was underfloor heating. It has turned out that the heating is only provided through the central ventilation system, essentially using warm air. The seller presents this as a particularly high-quality heating system that was even more expensive. We would have found underfloor heating, at least in the bathroom, very comfortable.

Can anyone share information about this type of heating? What are its advantages and disadvantages?

The house was built in 2002 and has approximately 145 m² (1560 sq ft).

Tobi
J
Joedreck
20 Jun 2017 14:56
As I mentioned, I would buy it significantly cheaper. Referring to the need for a complete new installation of an appropriate heat distribution system, I offer: the current price minus 30,000 to 40,000 euros.

Maybe the seller is also under pressure. You hold the strong cards.
T
Tobibi
20 Jun 2017 15:20
I don’t know if that would even be feasible.
There are no heating pipes installed in the house at all. So, the walls would have to be opened everywhere to lay pipes, then everything would need to be properly restored. All floors would have to be torn up, underfloor heating installed, and new floor coverings laid on top. Of course, a new heating system would also have to be purchased. Alternatively, it might be possible to connect to the district heating network available in the neighborhood, but that also involves costs. I have no idea if the ventilation system is designed to operate without heating.
I can’t estimate what this would cost.
J
Joedreck
20 Jun 2017 15:28
The affordable solution would be to have the underfloor heating milled in.
Alternatively, have radiators and a gas heating system installed.
However, the advice to consult an expert is the right approach.
Or completely decide against it.
T
Tobibi
20 Jun 2017 21:34
I don’t want to withhold the broker’s response when I asked him if he or the seller had a plausible explanation for the outrageous heating bill:

"Hello Mr. ...,

I can completely understand your concerns. I just reviewed the energy performance certificate. It clearly does not match the actual energy consumption. However, you need to know that the energy assessor prepared a demand certificate. This only calculates the building envelope based on standardized thermal transmission coefficients. Actual energy use is not taken into account here.

The energy certificate shows a final energy demand of 68.90 kWh, which corresponds to an energy rating of B.

If the building envelope were simply poorly insulated, the energy certificate would not look so positive. The heating system was also considered in the certificate, but only the technology of the air-source heat pump, not the heat emitters such as radiators, underfloor heating, or—as in this case—air distribution.

From my perspective, the extremely high energy consumption can only be explained by excessively intensive cooling of the house, which is, of course, quite significant. Mr. X has repeatedly told me that he has high electricity costs, but I always relied on the energy certificate. Since it was done by a true professional, I trusted it. If he had just printed it off the internet, I would have been skeptical. But Mr. Y is absolutely top-notch in his expertise.

I also spoke again with Mr. X. The electricity costs of 300 EUR per month for heating and hot water are indeed accurate.

What can I say? I think this heating system simply isn’t the most energy-efficient option. Perhaps the unit is no longer operating at its best efficiency. I tend to believe the demand certificate, which shows that this is an energetically very well-equipped house.

What I can fully understand, unfortunately, is that you have lost trust. I would have, too!

I don’t want to give you any recommendations, but I want to tell you what I would do in your situation—and this is really not about making money for me. I would not buy the house—you will feel that something was hidden from you every time you encounter a problem with the house. In such cases, my job would usually be to try to convince you otherwise—but I will not do that.

I respect all your decisions.

If I can still be of assistance, please feel free to contact me.

Best regards"
T
Tobibi
20 Jun 2017 21:36
I’m putting a checkmark behind this now and am glad I noticed it just in time. We had actually already scheduled the notary appointment. I didn’t expect the savings bank to operate like this and then only come up with empty excuses.
B
Bieber0815
21 Jun 2017 07:34
Tobibi schrieb:
Wow, I’m such a beginner. I should have requested an invoice much earlier.

I thought I had advised that, but it was in a different thread
https://www.hausbau-forum.de/threads/evtl-hauskauf-lwwp-moelicherweise-Groschengrab.24661/page-10#post-209604

Note: Inefficient building services reduce resale value.