How do i make a duct for cooker hood recirculation?

[Gary111]

I have had to replace my old recirculation cooker hood with a new one.
The old one had a kind of tee junction at the top near the vents to attach the ducting to, the new one doesn't have this, and I can't find a kit online.

I wonder if it's necessary to have that at all, if so how can I make one?

Thanks

 

[Deleted member 174758]

You can get ventilation ducting tees in various sizes, but are you sure the new cooker hood works that way? The ones I've installed (admittedly not that many) suck air in at the bottom, through a carbon filter then just exhaust into the (false) chimney or through vents on the top of the extractor. Post the make and model and maybe someone here has dealt with it and can confirm what's required

 

[Justin Passing]

If these guys don't sell it, it's definitely not "normal"! https://www.bes.co.uk/heating-ventilation/ventilation/ducting/

 

[foxhole]

I have had to replace my old recirculation cooker hood with a new one.
The old one had a kind of tee junction at the top near the vents to attach the ducting to, the new one doesn't have this, and I can't find a kit online.

I wonder if it's necessary to have that at all, if so how can I make one?

Thanks

Best to vent outside or it just recirculates the grease.

 

[Harry Bloomfield]

I have had to replace my old recirculation cooker hood with a new one.
The old one had a kind of tee junction at the top near the vents to attach the ducting to, the new one doesn't have this, and I can't find a kit online.

I wonder if it's necessary to have that at all, if so how can I make one?

Thanks

Recirculating is a really bad idea, all that steam and grease loaded air just being kept in the house. Do a proper job, vent it outside via a duct and a hole in the wall.

 

[Deleted member 174758]

One thing I found when fitting kitchens was that in houses where there was a recirculating extractor, the wall paper and ceiling above the cabinets was always a lot greasier and more yellow than elsewhere in the kitchen. But not everyone wants to pay the extra for coring the wall out and running the ducting - not too bad a job to do on a "standard" semi or terraced house, but somewhat more awkward on a 2nd or 3rd floor flat

 

[Harry Bloomfield]

One thing I found when fitting kitchens was that in houses where there was a recirculating extractor, the wall paper and ceiling above the cabinets was always a lot greasier and more yellow than elsewhere in the kitchen. But not everyone wants to pay the extra for coring the wall out and running the ducting - not too bad a job to do on a "standard" semi or terraced house, but somewhat more awkward on a 2nd or 3rd floor flat

True, but we don't know the OP's domestic situation, so always the best advice to avoid recirculation where possible and I heard something about extraction being a new requirement.

 

[Deleted member 174758]

Harry, I always hated those recirculating extractors, but it wasn't my choice, it was the customer's. If I was asked to core out I was happy enough to do it as it counts as a chargeable extra (they were never included in the fit price)

...I heard something about extraction being a new requirement.

Well, I did a bit of snagging/finishing on 5 new build houses maybe a month and a half back and they were all fitted out with recirculating extractors (but granted they were all electric hobs - I have always understood that gas hobs do have to vent outside). The company building them is a medium contractor who is building about 120 homes across two sites, so I'd have thought they'd know their stuff.

 

[Harry Bloomfield]

Harry, I always hated those recirculating extractors, but it wasn't my choice, it was the customer's. If I was asked to core out I was happy enough to do it as it counts as a chargeable extra (they were never included in the fit price)


Well, I did a bit of snagging/finishing on 5 new build houses maybe a month and a half back and they were all fitted out with recirculating extractors (but granted they were all electric hobs - I have always understood that gas hobs do have to vent outside). The company building them is a medium contractor who is building about 120 homes across two sites, so I'd have thought they'd know their stuff.

https://www.domex-uk.co.uk/help-advice/do-you-need-an-extractor-hood-in-your-kitchen/
Has the following to say on the matter

Do I really need an extractor hood?
In short – yes, you do need an extractor hood. Since April 2006, building regulations state that extract ventilation must be fitted in a kitchen which has been built from that date onwards. A kitchen will meet these regulations if the unclean air is extracted externally. It must also provide the extraction airflow rate which is detailed in the government’s Approved Document. A kitchen will not meet these regulations if the hood only filters the air and recirculates it around the kitchen.

Part F applies.

Maybe worth speaking to that site manager about Part F:.

 

[Deleted member 174758]

Part F applies.

Maybe worth speaking to that site manager about Part F:.

I stand corrected, however I wasn't the installer, so it's not my problem, Harry, as I only did some snagging work for them as a cover during holidays. Fortunately for me, they are not my employers, and it's presumably down to the contracts manager and the building inspector who signed off on all these houses. Good luck trying to talk to that CM - he's a complete AH to everyone as far as I can see

 

[Harry Bloomfield]

No problem, I was at first relying upon a vague memory, until I did the research.
I got the AH, but who or what is CM?

 

[Deleted member 174758]

CM = Contract manager - but in this case CM = AH because he was such a pleasure to work for