Different statements from Gu / Gü about the topic of heating

Hello dear forum,

I know the topic has been discussed countless times but due to different statements we are quite confused.

We are currently planning a single-family house 120-130 sqm (that’s enough for us),
2 full floors, turnkey,
solid construction, no basement.

Now the topic of heating came up.

Briefly about the companies:

Company 1: Does everything themselves or has the trades within the company.

Company 2: Only works with subcontractors from the region.

Which heating system should it be?!
We briefly let ourselves be explained what there is and how what works.

Gas vs. geothermal
Company 1: Geothermal would not be worth it. Gas costs about 70 to 80€ per month.
Electricity costs for heating about 50 to 60€ per month.

That makes a difference of about 20€.

But since the purchase of the geothermal heat pump is too high, it would not be worthwhile to install one.

Company 2: What kind of heating do you want?
Gas!
Why?
I explained to him what Company 1 told me.

He said that was wrong, often such statements are made because people don’t know or cannot/may not install it.

Also Company 2 told me: Gas heating should only be operated with underfloor heating since the new gas heating systems have an extremely low “preheat time” (I hope you know what I mean) of 38 degrees so my radiator would never really get warm.

And they would probably sell me old technology then.

Company 1, for example, did not tell me that.

Company 2 offered me an air heat pump which would be cheaper in the end since I save the gas connection and the pump or the fan outside would only run in the morning and evening.

Is that correct?

Best regards

About the air heat pump, it runs according to the demand (heat or hot water). I believe you can also only turn it on in the evening and morning. However, if the family of four wants to take a long shower around 2 pm, it can happen that there is only cold water...

Basically, energy costs money one way or another, no matter in which form.

Basically: these are all generalizations and therefore completely incorrect statements.

If you want to build with radiators, which I strongly advise against, then I would choose gas. Although the flow temperature (not preheating time) is important for efficiency, with gas it is by far not as critical as with a heat pump.

I would always operate heat pumps (in new buildings) only with underfloor heating. But the underfloor heating must also be designed for that. Flow temperatures of 38 degrees are too high to remain efficient.

Gas, on the other hand, is very undemanding and with the current prices, you might just break even compared to a heat pump. Because costs such as connection, maintenance, basic fees, chimney sweep strongly affect the total cost calculation at low consumption.

In addition, many companies charge hefty surcharges for the heat pump. Although this is unnecessary.

Specifically for me, in a new building this would mean: if the heat pump is offered much more expensively than the gas heating, I would choose gas.

Important for all types is the underfloor heating. For this, a room-specific heat load calculation is required. After that, the underfloor heating is designed.
Future-proof would be e.g. 30/26/21.
Meaning 30 degrees flow temperature, 26 degrees return temperature at 21 degrees room temperature.
You can set this within certain limits for each room. At least the room temperature.

For your information: I am also just a layman, but have been dealing quite intensively with building technology for 8 years.

All proposals are without own work. If a certain amount of own work were desired, there would be one or two other options.

Gas vs. Geothermal Firm 1: Geothermal would not be worthwhile. Gas costs about 70 to 80€ per month. Electricity costs for heating about 50 to 60€ per month. Makes a difference of about 20€. But since the acquisition cost of the geothermal heat pump is too high, it would not be worthwhile to install one.

Geothermal takes an extremely long time to possibly pay off. The green aspect is rather the priority there, or if you absolutely want to achieve a KFW standard that cannot be reached with gas without many additional measures. Since Firm 1 handles the trades themselves and argues this way, they will mainly sell gas heating systems.

Also, Firm 2 told me: gas heating should only be operated with underfloor heating, because the new gas heaters have an extremely low "preheating temperature" (I hope you know what I mean) of 38 degrees so my radiator would never get properly warm.

Complete nonsense. Of course, gas heaters can also be operated with higher flow temperatures if you absolutely want radiators throughout the house. Unlike an air heat pump, a gas heater becomes less inefficient at higher flow temperatures.

Firm 2 offered me an air heat pump, it would be cheaper in the end because I save the gas connection and the pump or the fan outside would only run in the mornings and evenings.

Just as much nonsense. Sure, hot water is often needed in the early morning or evening, so that is when it works most. But it is more efficient if a heat pump operates rather evenly. Especially during the daytime when the outside temperatures are highest, it can work more efficiently than in the cooler night or morning hours. If a photovoltaic system is installed as well, it can even make sense to heat more during the day to improve self-consumption.

All suggestions are without personal contribution. If some degree of personal input were desired, there would be one or two more variants.

I would be interested in those :)

I would be interested in those :)

My tip: trench collector