Construction costs are currently skyrocketing

You can sugarcoat anything. There are things you simply don't do. Good that it had no consequences for you. But please do not recommend such behavior.

Thanks for the tip about the heat pump. I will ask our BU about it. We will either get:

Bosch Compress i7800LMW or
Vaillant flexoCOMPACT exclusive VWF 58/4

It depends on whether the controlled residential ventilation with enthalpy heat exchanger is available from Bosch or not. If not, we will switch to Vaillant.

The concern is justified, recently someone here collapsed dead due to CO from the gas patio heater in the poorly ventilated but anything but airtight awning of his motorhome.

The awning must have been quite airtight after all. Carbon monoxide can only form if there is too little oxygen during combustion. In a normal, windy awning, that is impossible.

The awning must have been quite airtight after all. Carbon monoxide can only form if there is too little oxygen during combustion. In a normal, windy awning that is ruled out.

I’ll drive to the cemetery and tell the good man that he can’t be dead. Well, whatever, personally I wouldn’t take any risks with combustion in enclosed spaces, no matter how many people on the internet claim to have always survived that without problems. However, I also wouldn’t go to a poorly ventilated hookah bar anymore after reading about CO meter results and resulting health incidents there. Everyone has their own health quirks. Some only eat organic vegetables, others are cautious about carbon monoxide.

Well, I'm not saying it's unwise to have a certain respect for carbon monoxide. Nevertheless, it makes sense to understand how carbon monoxide is produced. Namely, during incomplete combustion due to insufficient oxygen. In addition, the exhaust gas removal must also be absent or defective. The awning was therefore sufficiently sealed to prevent both the supply of enough oxygen for clean combustion and adequate ventilation of the exhaust gases.

Carbon dioxide is not harmless at higher concentrations (w.f. >30,000 ppm) either. You can lose consciousness and eventually suffocate. But it also has to be airtight for that to happen, otherwise oxygen would eventually flow back in.