ᐅ Air source heat pump with a central ventilation system

Hello Forum,

Today we had a meeting with a home consultant. In our building specification, we planned for underfloor heating combined with an external air-to-water heat pump. Additionally, the consultant included a central ventilation system with heat recovery in the plan. The extra cost for this is about 9000€.

The question is whether this is worthwhile. So far, we have planned for a KfW-55 standard house.

Is this an extra commission for the consultant, or does it make sense in combination? What are the advantages and disadvantages? Somehow, I get the feeling of “belt and braces” here... but that’s just my gut feeling.

Thanks for your assessment!
Best regards, Andi

I consider a central mechanical ventilation system with heat recovery highly recommendable! However, it is definitely a luxury that you need to be willing and able to afford consciously.

The heating system simply provides warmth, while the ventilation system supplies the house and its occupants with fresh air!

New houses should no longer be built without a mechanical ventilation system with heat recovery unless it is possible to ventilate all rooms twice a day.

Energy stays inside the house, and the air remains fresh (in the sense of being renewed). Otherwise, the air quickly becomes stale.

I believe you can no longer achieve KFW 55 standard without mechanical ventilation with heat recovery. That’s how it is. A good investment, mechanical ventilation with heat recovery. We paid 12,000 euros 7 years ago, but never regretted it.

The recommendation is very good.

On the one hand, it is hardly feasible to cross-ventilate the house three times a day (as recommended). On the other hand, even if you can do it, the discipline to maintain this routine every day for years is a completely different matter.

Modern houses are as airtight as a plastic bag.

And they cost a lot of money. I would rather give up other things than a mechanical ventilation system with heat recovery.

Thanks for your comments. So, it might be better to skip the solar panels on the roof for now (they could be added more easily later) and keep the ventilation system instead… that actually sounds reasonable when you think about it.

This would mean it’s no longer possible to reach KfW 40+ standards, but KfW 40 would still be achievable…

I would always avoid solar thermal systems. But not photovoltaic panels! They are the only part of the house that actually earns money and pays off the loan by itself!