ᐅ KfW40 house offer with heat pump and mechanical ventilation with heat recovery— is it worth it?

Created on: 25 May 2019 21:19
Q
querys_
Hello everyone,
Today I received a house offer from a prefabricated house supplier.
They list the exhaust air heat pump Nibe F 750 with supply air module SAM 40 as the heating system. The maximum building heating load is said to be 7.5 kW.
Additionally, there is underfloor heating and a 180 L (48 gallon) domestic hot water storage tank.
The house is located near Cologne/Bonn Airport (for climate reference) and is about 120 m² (1,290 sq ft) in size (excluding the basement).

I have already read a lot of negative things about exhaust air heat pumps, so I want to ask again if this system is any good, and if not, what would be an alternative and how much more would that cost?

Thank you very much!
Q
querys_
29 May 2019 20:33
Jenpa schrieb:

Aren't eligible heating systems listed on the Bafa site?

Thanks, I just checked! The heating system offered is included!
Jenpa schrieb:

It might be that instead of a domestic hot water tank, you will heat with instantaneous water heaters at the points of use.
That wouldn’t be a big issue for me; I’ve never had it any other way in my life. At least I wouldn’t need to keep hot water ready when I don’t need it.
G
guckuck2
29 May 2019 20:34
querys_ schrieb:

Buderus Logatherm WPL 8 AR

I assume it is the WPL 8 AR T.
This model features an integrated 190 liter (50 gallon) hot water tank.

However, the 6 model should be sufficient if a ventilation system with heat recovery is installed. That option is about 1500€ cheaper.
Q
querys_
29 May 2019 21:08
@guckuck2 so the "T" is not included in the offer. The ventilation system is also no longer listed (I think it is missing now).
I will ask the prefabricated house supplier again.
Q
querys_
15 Jun 2019 18:57
After a lot of back and forth, I found out that the Buderus system does not include controlled ventilation and does not have a central hot water storage tank.

Last week, I had an interesting discussion with the company Nibe. Even the technician was not really convinced about the air-to-water heat pump.

In the end, the following solution came up:

Nibe SMO 40 + F2120 air-to-water heat pump + hot water storage tank
combined with ERS 10-400 ventilation unit.

Alternatively, instead of SMO 40, the VV320 could be used, but this would require a buffer tank for the heating system, which I actually don’t need with underfloor heating.

In the end, this should not be much more expensive than the offered F750 + SAM 40. Additionally, I can still receive a 2000 euro government subsidy (BAFA).