ᐅ Renovating Older Homes: Heat Pumps / Solar Energy / Gas / Oil

Hello,
we are taking over an old building from around 1900 in Switzerland that is still in its original condition. This means:
- Stove heating
- Double sash windows
- Uninsulated façade
- No gas connection

Currently, I have the following conditions:
- For tax reasons, it makes sense to spread the expenses over several years
- A new gas connection costs well over 20,000€
- Night electricity costs about 15 cents/kWh, daytime electricity 30 cents, gas about 17 cents, and oil slightly less

The windows definitely need to be renovated – there’s no way around that.
My question is: purely economically, even the operating costs (without investment) of a gas condensing boiler are already higher than those of an electric heating rod (even 106% efficiency can’t compensate for that).

At the moment, I am hesitant about the basic costs of connecting to gas or installing an oil tank. Therefore, an air-to-water heat pump with a 2 cubic meter (about 70 cubic feet) buffer tank could be an option. On the other hand, with the old building, I won’t be able to achieve very low flow temperatures since the insulation will probably have to wait, and I also can’t install underfloor heating everywhere.

What’s your opinion? Have there been significant advancements in heat pumps in this regard (e.g., “air-to-water high-temperature heat pumps”)?

I also have some garden space available, so a ground-source heat pump could be possible as well.

But what do I do when it gets a biting -20°C (-4°F)?

Regards
ALF_BE

Correct is:
"Off-peak electricity costs about 10.5 cents/kWh, daytime electricity 20 cents, gas about 11.5 cents, and oil slightly less."

ALF_BE schrieb:
....
- a new gas connection costs >> 20,000€...!!!

Where can you find something like that???????????????? In Germany, it costs about 2,000€ (~2k€).

ALF_BE schrieb:
....(even 106% efficiency does not change that).

Where would the extra 6% come from? The combustion efficiency should not be confused with the annual utilization rate. For a gas condensing boiler, it is about 80% depending on the share of heating/hot water.

ALF_BE schrieb:
....I am a bit hesitant about the basic costs for a gas connection or an oil tank right now.

Understandable given these connection costs!

ALF_BE schrieb:
....Therefore, an air-to-water heat pump with a 2-cubic meter (70 cubic feet) buffer tank is an idea.

Why this size of buffer tank?

ALF_BE schrieb:
....On the other hand, I won’t be able to achieve particularly low flow temperatures in the old building, since the insulation will probably have to wait and I also can’t install underfloor heating everywhere.

Abnormally high flow temperatures have a more noticeable impact on the naturally lower seasonal performance factor of an air-source heat pump than on a ground-source heat pump.

ALF_BE schrieb:
...But what do I do when it’s a biting -20°C (-4°F)?

Heat with a ground-source heat pump!

best regards

Heating with a ground-source heat pump was also my first thought. However, it must be ensured that this is technically feasible and approved by the authorities. If a ground-source heat pump cannot be installed for structural reasons, an air-source heat pump is a good alternative. Even in winter, at freezing outdoor temperatures, an air-source heat pump provides comfortable heat in a well-insulated house.

It is also attractive for retrofitting in older buildings where the geothermal heat source cannot be used due to structural limitations. In many cases, the existing heating system can continue to be used while saving on energy costs. If your house has a low insulation standard and therefore a particularly high energy demand, I would recommend a ground-source heat pump.

BerndJaro schrieb:
...However, it must be assumed that this is also structurally feasible and approved by the authorities.

This should apply to every solution.

BerndJaro schrieb:
...If, for structural reasons, a brine/water heat pump cannot be installed, an air/water heat pump is a good alternative.

Why specifically this one? There are much more interesting alternatives if an air-source heat pump is even considered at all.

BerndJaro schrieb:
...It is also attractive for retrofitting old buildings where using the ground as a heat source is not possible due to structural reasons. Often, the existing heating system can be reused while simultaneously saving on energy costs.

This is probably just a salesman’s tale :o
Kind regards.