ᐅ Exhaust hood with external ventilation for KfW55 standard

This is all quite complicated. How about a combination of a recirculating range hood and a decentralized ventilation system? Could the decentralized ventilation, which in my opinion is less effective than the exhaust hood at removing cooking odors, help reduce the load on the recirculating range hood?

Raiweired schrieb:

Could decentralized ventilation help reduce the load on the recirculating range hood, which in my opinion is less effective at removing kitchen odors?

Sure, it can help reduce the load, but why combine two systems here when better alternatives exist (exhaust ventilation for the range hood and central controlled residential ventilation)?

AxelH. schrieb:

Sure, relief ventilation is possible, but why combine two systems here when better options exist (exhaust ventilation for the cooker hood and central mechanical ventilation with heat recovery)?

In our case, exhaust ventilation for the cooker hood was clearly discouraged because we have a central mechanical ventilation system with heat recovery. This is certainly not a "better" alternative? Combining a central mechanical ventilation system with heat recovery and exhaust ventilation for the cooker hood seems contradictory to me.

At least this was confirmed by the kitchen fitter, the general contractor, and the ventilation specialist.

I think you can’t go wrong with a good recirculating cooker hood—I’ve seen it with a friend. He invested in a high-quality Berbel hood, and it’s definitely worth it... You just have to avoid installing "junk." If recirculating, then a proper hood.

It also seems strange to me to punch a hole in the wall if you want a "tight" house—especially when you also have a ventilation system. To me, that doesn’t really fit together.

i_b_n_a_n schrieb:

A good hood is one with a recirculation function and an activated carbon filter.

We are building according to the Energy Saving Regulation, and our general contractor also advised against an exhaust system.

After thorough consultation at the kitchen showroom, we are going for a recirculation hood with an activated carbon filter.

We were convinced at the kitchen showroom, and hopefully, it will work just as well at home 🙂

The issue with exhaust air systems—and why they are often discouraged—is that in a very airtight house, a large amount of air is expelled outside. You then have to calculate how much air is available inside the rooms and how much fresh air the mechanical ventilation system supplies. Only if everything balances out is an exhaust air system feasible. The hole in the wall is not really a valid argument. With a properly installed thermal box, the hole only exists when the exhaust system is running, because the flap only opens then. With a correctly installed thermal box, every house passes the blower door test (at least if there are no other weak points). Besides, all of us probably have much larger openings in the house that are opened regularly, since house and patio doors are nothing different.

This is how it was explained to us as well. It was discouraged, not because it doesn’t work, but because it is very complex and therefore expensive when combined with a mechanical ventilation system with heat recovery.

For example, an automatic window opening would need to be implemented so that a window opens by itself as soon as the exhaust air system starts.

However, we didn’t listen to this in detail since we planned to use a recirculation system anyway.