ᐅ What is currently the best heating system?

EarlGrey schrieb:
... And as far as I understand, first clarify the construction method, then have the actual demand/consumption checked, and only after that comes the selection of the heating system.

Correct!

EarlGrey schrieb:
... I currently find the idea of a solar thermal system combined with some photovoltaic panels along with a controlled mechanical ventilation system with heat recovery to be the best option.

Why?

Best regards

So Euro, you ask a lot of questions.

Well, my main goal is independence. I am really hoping a lot from the solar thermal system, which will heat all the domestic hot water and water for the planned underfloor heating.

Additionally, photovoltaic panels so I can use my own electricity and reduce the amount I need to buy.

And the heat pump is supposed to serve as the heating source within this whole system. A ventilation system with heat recovery is almost a must if I’m planning a passive house or low-energy house.

I kindly ask once again for corrections to my rather limited perspective on this topic. Or have I really considered everything this time?^^

Regards, Earl

EarlGrey schrieb:
...Well, my main idea is independence. I am hoping quite a lot from the solar system that heats all the domestic hot and heating water (for a planned underfloor heating system).

This is a misconception, especially when there is a high demand—the solar thermal system delivers little or no output (during heating operation)! Is the investment in it then justified?
Solar thermal system – domestic hot water: a pure sham under “normal” usage habits in a single-family house!

EarlGrey schrieb:
...Additionally, photovoltaics so I can use my own electricity and reduce what I draw from the grid.

A completely different league! Heat pump + photovoltaics => a very sensible concept for heating and domestic hot water!

Best regards.

€uro schrieb:
It’s a misconception that a solar thermal system provides little to no output when there is high demand (heating operation)! Is the investment for this really justified?
Solar thermal system - domestic hot water: A total gimmick for "normal" usage patterns in a single-family home!
A completely different league! Heat pump + photovoltaic system => a very sensible concept for heating and hot water!

Regards

Okay, so in your opinion, it’s better to rely on a heat pump (air-to-water heat pump) and a good photovoltaic system. Correct? And why?

Is the efficiency of a solar thermal system really so negligible? Do you think I should leave out the solar thermal system entirely or just consider it as a supplementary option?

Best regards, Earl

EarlGrey schrieb:
Ok, so in your opinion it’s better to focus on a heat pump (air-to-water heat pump) and a good photovoltaic system. Correct? And why?

Correct, heat pump + photovoltaics. The type of heat pump that makes sense depends on the results of a preliminary basic assessment (actual demand (capacity, energy) for heating and hot water). With higher demand, for example, a ground-source heat pump with vertical probes, ground collectors, or trench collectors will be more effective. With moderate to low demand, the better annual performance factor of a ground-source heat pump is less important, so an air heat pump is often sufficient here.

EarlGrey schrieb:
...Is the efficiency of a solar thermal system really so negligible?

Efficiency values are performance-related "snapshots" and therefore less relevant. For the owner, the more important figure is the energy-related annual utilization rate.
Example: A heat generator based on combustion principles has a combustion or boiler efficiency of 95%. However, the system’s annual utilization rate is only about 60%. Forty percent of the input (purchased) energy is lost without any benefit. How meaningful is that efficiency value then?
Example: Controlled ventilation with heat recovery: The manufacturer specifies a heat recovery efficiency of 80% (performance-related). The actual utilization rate, depending on the climate region, is only about 30 to 40%.
Example solar thermal system for hot water: The energy source (sun) is free, but only fractions of this can be practically used. Problems include the storage challenge and the daily variation of solar irradiance (not constant). In a commercial facility with distributed hot water demand throughout the day, solar thermal makes sense; in a single-family house, where occupants leave in the morning and return in the evening, less so. Certainly, some kilowatt-hours will be "harvested" over the year, but this yield usually does not correspond to demand or justify the investment. The theoretically favorable energy efficiency often exists mainly on paper (e.g., in official subsidy proofs).

EarlGrey schrieb:
...In your opinion, should I completely omit the solar thermal system or just plan it as a supplementary measure?

Completely omit it and focus on the essentials! System installers often struggle to make even simple configurations energy efficient because there is usually insufficient basic assessment, planning, and dimensioning of the system. The more components involved in heat generation, the lower the overall utilization rate, despite sometimes quite high investments.

€uro schrieb:
The theoretically optimized energy efficiency mostly exists only on paper (e.g., KfW certificate).

Which heating system is currently the best?

Gas condensing boiler + wood stove / Bullerjan / Chief stove
Gas condensing boilers have proven reliable and are also suitable for individual apartments.
Central heating systems cause too much loss – the condensing boiler is more efficient in that regard.

Thermal solar systems can be forgotten. Hardly any savings (less than 15%) After 15 years they become waste – Anatol reinvestment.
A waste of money. Better to save that money and invest in a photovoltaic system? (just my opinion)

In general: Anything with too much technology doesn’t work. Ultimately, it’s a matter of comfort.
Do you have problems carrying hardwood briquettes? Then use a wood chip stove.

We are testing an AEG eco electric water heater for the shower and kitchen. We don’t need one for the bathtub.
Electricity costs for the shower heater: about 100 Euro.

Heating is done by a gas condensing boiler down to 12°C (54°F). The rest is covered by the wood stoves.
Fuel: a handful of pellets to start, otherwise only hardwood briquettes. Pure beech wood; spruce wood was yesterday.

PS: In the end, you need to take a calculator and do the math.
Unfortunately, so-called "specialist companies" push a lot of nonsense, especially at trade fairs, because everyone claims to have the best solution.