ᐅ New heat pump to replace oil heating with existing radiators

ajokr2025 schrieb:

... and above all: reliable equipment is subsidized at 55%. Whether the DWW unit is included in the list of eligible systems, I don’t know.
Then the DWW offer is only cheap because you don’t get any subsidy. Or rather, the provider can’t claim it.

The subsidy aspect is actually contractually guaranteed. I can withdraw at any time if the KfW does not cover 50% of a maximum of 30,000 Euros. It even states that DWW will refund the money if it turns out later that KfW partially reclaims the subsidy when reassessing the figures (do they really do that sometimes, or is that just a scare tactic?) I am still seriously considering the R32 option. They strongly advised against propane because there have reportedly been explosions with customers, and I was informed that I would bear the consequences myself.

I am very grateful to everyone participating in this lively forum discussion; it’s making me rethink everything. Two more offers are still in the pipeline. If it gets more expensive, I’ll try to secure a subsidy of around 45,000 Euros (for a two-family house).

Indoor air handling units cannot use R290 at all. Air conditioners still rely on R32 because the flammable R290 is only allowed to be installed outdoors, and refrigerant lines are not permitted to run inside.
Although R32 is not explosive, it is just as deadly if inhaled in enclosed spaces. As long as the refrigerant lines remain intact, both gases are safe.
There have been cases of explosions involving R290 when a heat exchanger froze, causing refrigerant to enter the heating circuit and be vented into the heating cellar through a quick-release valve. This is why such vents are only permitted on the outdoor unit.

ajokr2025 schrieb:

Indoor air conditioning units are not compatible with R290 refrigerant at all. Air conditioning systems still rely on R32 because the flammable R290 is only allowed to be installed outdoors, and refrigerant lines running indoors are not permitted.
Although R32 is not explosive, it is equally dangerous if inhaled in confined spaces. As long as the refrigerant lines remain intact, both gases are safe.
Yes, there have been explosions with R290 caused by a frozen heat exchanger, which allowed refrigerant to enter the heating circuit and be vented into the heating basement via a quick vent. This is why such vents are only allowed on the outdoor unit.

THANK YOU! And would you advise me to involve DWW only if I have no other options with different companies? Or is R32 an absolute no-go?

If you want or need cooling, you can’t avoid R32. However, I still can’t come to terms with the all-in-one solution.

strzata schrieb:

I am still seriously considering the R32. They strongly discouraged me from using propane because there have supposedly been explosions with customers, and they informed me that I would have to bear the consequences myself.

That settles my serious consideration. Anyone who tells such nonsense is out of the question for me. They also sell electric blankets to seniors.

ajokr2025 schrieb:

If you want or need cooling, you can’t avoid R32.
However, I still can’t warm up to the all-in-one solution.

Cooling would be a real bonus. In summer, I had nearly 40°C (104°F) at night in the bedroom on the upper floor under the roof... but the heat was throughout the entire house. Outside there was no shade.
What else do you have against R32 that might stop me?