ᐅ What is currently the best heating system?

By "secure," I mean without any unexpected costs, especially in terms of energy consumption.

I don’t quite understand your statement. Everyone says that uninsulated houses should not be heated with an air source heat pump because these pumps are supposed to be overwhelmed in such cases.

I just noticed you wrote: ground source heat pump

First of all: I am also just an amateur.

I just wanted to clarify that your generalization between gas condensing boilers and air-to-water heat pumps cannot be correct.

I simply based my considerations on the fixed and variable costs of different heating systems. To illustrate the extremes, I used gas condensing boilers and geothermal heat pumps on the heating side, and highly insulated and uninsulated on the building side.

The air-to-water heat pump you mentioned should fall somewhere between the gas condensing boiler and geothermal heat pump in terms of both fixed and variable costs. Where this type of heating system reaches its optimum needs to be calculated. You can’t generalize this.
Furthermore, the building energy efficiency rating (e.g., KFW classification) changes due to the heating system type, not the other way around.

Musketier schrieb:
....The higher a house’s heating demand, the larger the share of variable costs (energy carrier costs) in the total expenses. The lower the house’s heating demand, the lower the fixed costs (maintenance, purchase, interest) of the heating system should be.

Correct. However, I would phrase it differently overall: The higher the demand for heating and hot water, the higher the requirements for energy efficiency. Therefore, to find the right overall solution, a basic assessment (actual demand (capacity, energy) for heating and hot water) must be carried out.

Musketier schrieb:
....High fixed costs and low variable costs = e.g., ground source heat pump
Low fixed costs and high consumption costs = e.g., gas condensing boiler

This is not generally accurate!

Musketier schrieb:
....It therefore makes no sense to install a very expensive heating system with minimal consumption in a “passive house.” In this case, a gas heating system could actually be the cheaper alternative. The only question is whether the “passive house” title would still apply.

Correct, because the sum of the costs is the same. It is possible to build a passive house quite cheaply if certification is waived. However, if one is focusing exclusively on subsidy incentives, there is no way around certification.

Musketier schrieb:
....In an uninsulated older building, on the other hand, a heating system with high fixed costs and low consumption (e.g., ground source heat pump) would be the better option.

Correct! However, existing buildings come with limiting conditions (heating surfaces, hydraulics) that often make the use of brine heat pumps and especially air source heat pumps impractical. Of course, manufacturers do not highlight this in their advertising hype. You will find claims like “heat pump suitable for older buildings,” “heat pump with supply temperature up to 60°C (140°F) and higher,” etc. Many have fallen for this and end up with high consumption costs despite relatively high investment (capital) costs.
Anyone relying solely on the vendor or builder in these cases will ultimately be left stranded. An exact basic assessment was naturally "skipped" in these cases.

Best regards

NB: There is no ultimate heating system, as the specific boundary conditions differ significantly.

Unfortunately, the past few winters have been somewhat colder, making air source heat pumps less efficient than the manufacturers probably anticipated (because of global warming).

“Global” warming does not mean that it is getting warmer everywhere. For example, in northern Germany, it is getting colder. But that is just a side note.

A blanket rejection of the question about the best heating system, as some do, is just as wrong as giving a general answer. Many factors need to be considered, such as the orientation and pitch of the roof, soil conditions, climate zone, hours of sunshine, average temperatures, and so on. These are all external influences. Once these are defined, it is possible to find the best solution for a single-family home (in my opinion, as I said).

If the focus is on independence rather than cost, I see the answer to the best heating system question in a solar thermal system. A very large collector area for the solar system, ideally combined with photovoltaic panels to produce some electricity for your own use (feeding back to the grid I consider not worthwhile), and a very large storage tank. The exact size depends on the size of the building. I do not want to write a long essay now, but for any other system, I would immediately think of significant disadvantages regarding dependency. Of course, with solar you depend on the sun, but that is not an energy company.

Hello everyone,

I'm just chiming in again to say thank you for all the posts and information. I really appreciate it. However, I still can't make a definite decision. This is mainly because the final construction method has not been determined yet. From what I understand, the construction method needs to be decided first, then the actual demand/consumption should be assessed, and only after that comes the selection of the heating system.

At the moment, I think the idea of a solar thermal system combined with some photovoltaics, together with a controlled ventilation system with heat recovery, is the best option.