ᐅ Heating via ventilation system with heat pump

Mycraft schrieb:
And of course, it’s more expensive initially since it combines ventilation and heating…

Not necessarily. You completely save on underfloor heating and all the piping for the heating system. If controlled residential ventilation is considered as a given, the exhaust air heat pump has a clear advantage in terms of investment costs. This is one of the reasons why a passive house doesn’t have to be more expensive than a KFW house. If you “overdo” the insulation, the investment costs for the heating system eventually decrease significantly.

I only explained where the statement that the heating system was expensive to purchase might have come from.

Mycraft schrieb:
I was just explaining where the idea might have come from that the heating system was expensive to purchase.

Ah, okay, I had read it differently.

@Tobibi Is there anything that supports the air heating system? Stove, photovoltaic panels, solar thermal?

@Alex85: I've noticed a few times that you equate exhaust air heat pumps with air heating systems. They are definitely not the same.
This is just a note because it can be easily misunderstood and is not meant to start a fundamental discussion.

DNL schrieb:
I’ve noticed a few times that you equate exhaust air heat pumps with air heating systems. They are by no means the same.
This is just a note because it can be easily misunderstood and is not meant to start a fundamental debate.

Guilty as charged.

The problem with exhaust air heat pumps is that they cannot supply external energy (except for the electric backup heater). This means the building must practically not lose any heat energy or even gain some passively, for example through solar gains, for this heating method to work.
It becomes especially critical if the heat is also supposed to come from the indoor air itself. To achieve this (as if the idea of a perpetual motion machine warming the indoor air wasn’t challenging enough), you really need passive houses, net-zero energy houses, or even plus-energy houses.
So no, of course, exhaust air heat pumps are not inherently air heating systems, but when installed in the wrong building (which seems to be often the case due to low investment cost), they effectively become one.

Now, I’m not sure exactly what you mean by "air heating." The common system is actually the air-to-air heat pump, meaning energy is drawn from indoor air and transferred back to air. In my opinion, this also comes with comfort drawbacks, since having warm air blown directly onto you from a convector-type device is unpleasant. A surface heating system is much more comfortable in comparison.

Even in the wrong building, it doesn’t become one. The AWP that Viebrockhaus and many others install in their houses is an air-to-water heat pump. It extracts exhaust air and heats the underfloor heating.