Cooker extractor vent making house cold.

cheif kaiser

Just had a new cooker and extractor installed and noticed that the floors upstairs which are over the ducting, are freezing, making the rooms cold.

When I checked the vent cover outside I noticed that the hole they drilled in the wall is much bigger than the ducting. The ducting does not seem to be attached to anything, it is basically just sitting on the ceiling inside the hole and is covered with just a regular vent cover so no wonder that cold air is getting in.

I assume this is not the way that ducting is supposed to be installed? What can I do to fix this? How do I seal up the big gap around the ducting and is there a special vent cover that should be used for ducting?

Thanks.

dathi

any chance of a few photos so we can see what you are talking about

cheif kaiser

dathi wrote: »

any chance of a few photos so we can see what you are talking about

Will try get a few photos tomorrow but work nights so difficult to catch a good day time picture.

Basically the cooker is on one side of the house and extracts to an outer wall on other side of house, meaning the ducting runs the full width of the house through the ceilings. The ducting they used is just the white cheap kind (although I did see them in the kitchen with a big length of the foil type and must have swapped it when I wasn't looking ) The vent to outside is exactly the same as this
.

I put my hand up into the ceiling over the extractor and can feel a very cold draught.

Should the ducting be insulated and is the vent used, the correct kind?

Thanks.

Water John

Use expanding foam, around the outside hole, comes in a spray type can.
The wind getting in the opening is probably your main problem. Doubt if the ducting is causing the cooling of the floor.
Some vents have fixed openings, others have flaps the close down, when air is not being pushed out through them.

cheif kaiser

Water John wrote: »

Use expanding foam, around the outside hole, comes in a spray type can.
The wind getting in the opening is probably your main problem. Doubt if the ducting is causing the cooling of the floor.
Some vents have fixed openings, others have flaps the close down, when air is not being pushed out through them.

Thanks Should I change the vent cover to one of those flap type, would that make a difference?

Water John

I now use a fixed one but there are flaps on top of the extractor that prevent draught. Turn off the fan switch and then feel, with the back of your hand to see is there a breeze.
Foam around the vent I think is more important.

listermint

Foam around the vent and put attic type insulation around the pipe in the floor area to insulate the pipe from the house

cheif kaiser

listermint wrote: »

Foam around the vent and put attic type insulation around the pipe in the floor area to insulate the pipe from the house

Can't really get into the floor as laminate laid on top of floorboards.

I was thinking I could buy some insulated ducting, attach this to the end of the ducting that is in place. Pull it all through from the outside, thus removing the rubbish ducting and replacing it with the insulated, without having to pull up floorboards?

I could them just fill around the hole with the foam and attach a new flap vent?

listermint

cheif kaiser wrote: »

Can't really get into the floor as laminate laid on top of floorboards.

I was thinking I could buy some insulated ducting, attach this to the end of the ducting that is in place. Pull it all through from the outside, thus removing the rubbish ducting and replacing it with the insulated, without having to pull up floorboards?

I could them just fill around the hole with the foam and attach a new flap vent?

Yep that works too

dok_golf

It cant be the ducting itself that is making the rooms cold. unless the extractor was installed the wrong way around. If anything, it ( as its pulling warm moist air from cooker) should heat the rooms. As someone above said, it's most likely to be a cold draught coming in where the installers didn't seal around the outside vent properly.

cheif kaiser

dok_golf wrote: »

It cant be the ducting itself that is making the rooms cold. unless the extractor was installed the wrong way around. If anything, it ( as its pulling warm moist air from cooker) should heat the rooms. As someone above said, it's most likely to be a cold draught coming in where the installers didn't seal around the outside vent properly.

The cooker is only really used once a day so any hot air pulled from cooking would be minimal. I was thinking that air was coming in through the cheap vent and causing the ducting to make the ceiling space cold. I also would not be a bit surprised if the ducting is done in more than one full length and may have leaking along the tube. I also heard that insulated ducting cuts down on the noise level which is really noisy!

May as well rip the whole lot out and do it correctly