Exhaust air / supply air for kitchen hood

Hello,

we want to build our kitchen relatively open. We now have this in a rented house with a relatively good exhaust extraction system (600 m³/h rated capacity, approx. 0.5 m Aluflex hose DN150 to the wall box) and are satisfied with the performance.

We are not satisfied with the requirement to always have to open a window.

However, the kitchen in the new building is not on an exterior wall, so there will be a few meters more of ducting for the exhaust air. Options would be, for example, to run about 4-5 m of duct through the roof, which would probably require at least two 90° bends. Alternatively, one could go horizontally through the technical room to the north with a 90° bend. Also about 4-5 m of duct. Both options would allow the blower to be mounted outside the kitchen and thus reduce the noise level.

Now we still need supply air. Could one possibly run it under the floor slab and outside have an intake chimney like for central controlled residential ventilation? Then you would need a motorized damper to make the whole thing airtight when not in operation.

Or is the whole effort not justified and we should use recirculation air?

We have a recirculation system with an activated carbon filter and are very satisfied with it, thus no warm air is blown outside, no supply air problem, and no air outlet to the outside...

Hello,

are you even allowed to install exhaust air in your new building?
In certain KfW new builds, this is not always permitted due to energy efficiency.
For this reason, recirculation technology has drastically improved in recent years.

Basically, an exhaust air system with an external motor is the gold standard.
The duct length should be at least 3 meters because of resonance noise, which can occur at less than three meters.
So this is not a problem for you.

An extra installed supply air is certainly possible, but questionable whether the effort is worth it.
Or whether an internal motor with a special wall box is used.
This then has a separate supply air opening.

Best regards

Hello,

take a look at the recirculation hoods from "Berbel."

We have a Berbel with a catalyst in the activated carbon filter, so we never have to change the filter media again.

We have been using the recirculation hood since February 2015 and are more than satisfied with it.

Regards,

Dirk

I have a colleague with a Berbel hood, which he operates both with exhaust air (summer) and with recirculation air (winter).

According to him, there is a significant difference between the two modes of operation; the system is much more effective in exhaust air mode.

I only run a Berbel in exhaust mode -> never anything else.