ᐅ New heat pump to replace oil heating with existing radiators

nordanney schrieb:

That would already end my "seriously considering." Anyone who says such nonsense would be out of the picture with me. He also sells electric blankets to seniors.

Okay, but see #33. What’s your take on that?

I decided to use R290 for heating and R32 for cooling. The cooling system is entirely financed through the subsidy for the heating. The price difference per kW is quite significant.
If one of them fails, the other will still work until the builder arrives.

strzata schrieb:

Okay, but see #33. What’s the deal with that?

Nothing. Yesterday, an electric car caught fire. So? Old cars only at your own risk? The day before, the neighbor’s oil heater caught fire – is oil really that dangerous? Oh, and an apartment building exploded due to a broken gas line.
R290 has been used for decades on old campsites and in gardens. It is just as hazardous as R32 and similar refrigerants, but not harmful to the environment. That is why R32 is being phased out. It is already partially banned and will soon be for heat pumps as well.
R290 is already common for air conditioning and will be the standard in the future.

Okay, to keep it relatively brief: the supplier should take you to the house that exploded and show you what happened. I suspect they won’t do that. They just want to get rid of inventory.
Then: if it’s 40 degrees Celsius (104°F) upstairs, your house insulation isn’t just bad – it’s really poor. Or it’s so good that the heat stored there can’t escape. I believe the first is the case.
Then once again, the question: why do you want to switch to a heat pump now? At over 80 years old, it will never be cost-effective for you personally.
The annual performance factor is simply false; it will get warm, but with horrendous electricity costs.
As a “young person,” I don’t have to fully understand your requirements in terms of content. I should listen, take them in, and consider them when giving advice here.
My advice is: keep running the oil heating until the end, as long as it still works. Alternative: have a used oil boiler installed by someone currently renovating.
If you want to do it thoroughly: hit the pause button, gather information, gather information, gather information.
The first step now would be to install a heat meter and try to see how far you can reduce the supply temperature after a hydraulic balancing without losing comfort. Then replace radiators selectively so that during the core winter you reach 40 to max. 45 degrees Celsius (104 to max. 113°F) supply temperature. By spring, you will have all the necessary data to obtain informed and independent offers.
If that is too much for you, I will be honest: a heat pump in your situation will not save you money, you will face a high investment with high ongoing costs, and therefore a heat pump is the absolutely wrong choice.

Joedreck schrieb:

Then: if it’s 40 degrees Celsius (104°F) upstairs, your house insulation is not just bad, it’s really poor. Or it’s so good that the heat inside cannot escape. I say the first is true.

You can insulate as much as you want. After a week of sunshine at 40°C (104°F) outside, the insulation is basically saturated. With wood fiber insulation it’s slightly better than with mineral wool, but only slightly.
In winter, the escaping heat is delivered through heating elements; similarly in summer, the excess heat must be removed with air conditioning units. Nothing more, nothing less. Radiators are not suitable for cooling because condensation forms on them. With underfloor heating you can cool a bit, but the humidity remains in the air. Air conditioning removes the moisture along with the heat.

That exploded house actually existed. You’re not allowed to post links here, but try searching for “frost damage disguised as explosion.” I already mentioned the simple damage prevention.
There is a monoblock air conditioner on the German market, but you have to place the outdoor unit containing R290 yourself on the balcony and seal the balcony door airtight around ventilation ducts so no heat can enter. Not very practical.
Otherwise, manufacturers insist that R32 is indispensable for them and are therefore exempt from the ban. Should a better and equivalent refrigerant become available, they will use it.

The specific use of heating and cooling with the same outdoor unit and no other heat source is indeed not necessarily future-proof. So yes, they want to clear out their inventory. I also feel a bit uneasy when devices from East Asia are relabeled in “German heat pump factories.” The only German part is the seller.

It is by no means the case that well-insulated and non-air-conditioned houses have 40 degrees Celsius (104 degrees Fahrenheit) in the attic at night during summer. I have only experienced this in poorly insulated houses. However, the original poster can provide the actual data regarding the really good insulation, so we have reliable information.