Kitchen ventilation: Outside fan to suck air out?

andre_xs

I had the following idea, but not sure I'm missing something: Would it be possible to have an external fan (i.e. attached to the outside wall were the outlet of the kitchen hood ductwork is) which 'sucks' the air out as an alternative to the 'pushing' fan in the cooker hood (which would need to be removed)?

Would solve the noise issue of these things...
(the electronics for controlling them might then be separate, but that wouldn't be a problem)

As an additional thing, our ductwork is pretty weird (old house), am I wouldn't be 100% it is totally intact, their might be small leaks. A 'sucking' fan would suck air from the leaks and transport it outside (which is fine), the 'pushing' cooker hood fan on the other hand would blow warm humid air out of the leaks, which easily can result in mould etc.

Edit: If somebody knows a good seller for such stuff, I'd be grateful. I only found one which looks ok and is ok pricewise. Most stuff is industrial ventilation, which might be a bit over the top :-)

Edit2: What I just realised, part of our ductwork are these flexible rectangular hoses (with the wire) - they might collapse / be pulled together and prevent air from flowing?

Fire_Fox

Flexible ducting is discouraged for new ventilation installs (see Building Regulations): it is easily damaged and can mess with air flow apparently.

Read up on in-line fans, and 'silent' kitchen fans. Note that these would have to be run for much longer to be equivalent to the BRegs air flow requirements for a cooker hood (30 litres/sec or 60 litres/ sec depending on location).

Consider consulting a BPEC Domestic Ventilation Installer. They should have the skills and knowledge to put together an integrated system suited to your unique property.

Jonesya

These for example, and I'd use them with rigid duct
https://www.fastlec.co.uk/ventilation-extractor-fans-domus-extractor-fans-external-centrifugal-fans/

But bear in mind there will still be some noise but now it will be outdoors, so need to think if it would be a nuisance to anyone like the neighbours.

FreeBear

Fire_Fox wrote: »

Flexible ducting is discouraged for new ventilation installs (see Building Regulations): it is easily damaged and can mess with air flow apparently.

Not so much "can", more does mess with the airflow. A smooth rigid duct will allow quite a bit more air to flow and will also be a fair bit quieter. The ducting also needs to be the appropriate size for the expected air flow, distance, and fan specifications.

The shorter the ducting, and the fewer bends, the better.