Bad cooker hood vent

[DiyNutJob]

I need help with the cooker hood vent. The space around the the ducting opens into the house letting in air and dust, probably some back flows as well. How can I make it all better please? The americans on youtube cry about plastic ducts are bad for fire safety. Is the situation same for the UK? I can see aluminium ducting available. I believe aluminum burns just as well. Is there any point to it at all?

The ducting end isn't attached to anything.

 

[Deluks]

What are the sizes of the ducting and of the opening?

Also, where are your flaps?

 

[DiyNutJob]

The ducting is 125mm (or maybe 120mm). The hole on the plastic face plate is 150mm ID. The face plate will be destroyed if I were to take it off.

There are no flaps. But I do want flaps. The face plate dimension is 172x172mm.

 

[opps]

Stainless Steel Wall Outlet Gravity Flaps

An external wall outlet for improving ventilation with cooker hoods, tumble dryers and other high-powered appliances.This 150mm vent comes with four anti-backdraught shutters which open during fan operation, and close when the fan is switched off – this helps to prevent external air flow or wind...

www.toolstation.com

There should be enough play in the ali duct to enable to secure it to the flap using a really big jubilee clip.

Amazon.co.uk : jubilee clip 150mm

 

[opps]

If plastic ducting from an extractor is a fire risk, there is something very wrong with the initial set up.

The temperature of the air from the hob should not pose a problem, provided that the minimum heights have been observed.

 

[DiyNutJob]

Multiple problems with that. Not looking for a bling on the wall. If the flaps are metal, it will be heavy and restrict air flow.

This is most likely what I need in additional to a reducer to 120/125mm:

White Duct Gravity Flaps 190mm x 190mm / 150mm Extractor Fan Air Vent Grille 5902904998894 | eBay

Find many great new & used options and get the best deals for White Duct Gravity Flaps 190mm x 190mm / 150mm Extractor Fan Air Vent Grille at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

 

[opps]

Multiple problems with that. Not looking for a bling on the wall. If the flaps are metal, it will be heavy and restrict air flow.

Jesus wept, it was the first link that I came across. The metal flaps will however, probably weigh less than plastic ones.

The next time you ask for advice, I will steer clear. It really isn't worth the hassle.

 

[DiyNutJob]

The metal flaps will however, probably weigh less than plastic ones.

Highly improbable, although not impossible. Your ego shatters like glass. Let me give you a like to make it all better. But I will go plastic, the gut boss says so.

 

[opps]

Highly improbable, although not impossible. Your ego shatters like glass. Let me give you a like to make it all better. But I will go plastic, the gut boss says so.

I don't care which you go for, I am not part of the plastic Vs metal flap cabal. There is however something very wrong in your life, and quite frankly, I don't care, nor do I want to get sucked into your psychosis.

Fill your boots, and best of luck...

 

[Deluks]

I've extract-ed a lot of entertainment from this thread. Thanks fellas!

 

[DiyNutJob]

After extensive research, a flappy vent has been ruled out. It wears out, or gets blown apart by wind. I can now see the reasoning behind metal vents. On balance, the original vent is best. I am unable to find a direct replacement. The closest is the following, with a 5 year warranty. Not that I care about the warranty, but the plastic should be reasonably robust. Once installed correctly, it should last a liftime.

Plastic Fixed Blade Louvred Wall Grille Extractor Fan Cover Duct Vents 4" 5" 6" | eBay

Find many great new & used options and get the best deals for Plastic Fixed Blade Louvred Wall Grille Extractor Fan Cover Duct Vents 4" 5" 6" at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

 

[Harry Bloomfield]

After extensive research, a flappy vent has been ruled out. It wears out, or gets blown apart by wind.

I beg to differ, our extract hood 'flappy vent' and likewise the bathroom, were installed by me 20 years ago and the are still good as new, working how they should. Idea is - the pressure of air from the running fan should be able to open them, but if the wind blows against them, they close to prevent dirt/cold air entering.

 

[DiyNutJob]

The existing vent lasted 30 years. If I didn't have to destroy it to redo it, it would last forever. There is only one flappy vent on the market with insect guard and it looks flimsy. For lowest risk, I will stick with the old style. One possible improvement is adding an inline non-reverse thingie near the vent. At the moment this is part of the cooker hood, which means I have a whole column of cold air inside the ducting inside the house. This acts like a heatsink and bad for the winter.

 

[Harry Bloomfield]

At the moment this is part of the cooker hood, which means I have a whole column of cold air inside the ducting inside the house.

No surprise there - because what you have, doesn't fit and lacks a shutter anyway.

 

[opps]

The only type of vent that I have (over the years) come across that flaps in wind is the type that has a single flap and a cowl over it.

Manrose Cowl Vent Brown 100mm x 100mm - Screwfix

Order online at Screwfix.com. HIPS polystyrene. Suitable for commercial and domestic use with 100mm round pipe or 110 x 54mm rectangular ducting. Not suitable for gas appliances and must not have grilles or flaps obstructed designed for products such as ventilation and extraction fans, etc. FREE...

www.screwfix.com

And that was on an attic conversion on a semi-detached house. From memory, I used a foam buffer to stop the slamming noise on particularly windy days.