Sealing up trickle vents?

[MJNewton]

I am in the midst of retrofitting an MVHR system and am wondering what, if anything, I should do about my window trickle vents once complete. I could just leave the cover flaps closed but a) I'm not sure how well they seal (probably well enough I'm sure), and b) whilst the flaps cover the inside hole the outside hole remains open (with just an insect screen) and so cold air can still enter the window frame cavity (they're multi-chamber UPVC).

 

Whilst I am confident this MVHR system will be 'for life' I don't want to remove the potential for reversal and so thought expanding foam in the vents might fit the bill. It'll work (seal/insulate) well and I think should be removable if need be by hacking at it with a suitable tool and having a vacuum cleaner suck all the bits out.

 

Any thoughts? Even just the advice to close the vents and get on with my life?!

 

 

[Simplysimon]

take the vent covers off, stick some clear gorilla tape over the holes. would suggest masking off the outside area of the covers prior to taping as that stuff sticks! trim back after refitting covers.

[MJNewton]

Hmm, yes, that would work and sounds less radical / more reversible. Even less-sticky-than-Gorilla-tape tape should work as the covers will both protect and keep it in place. 

[joe90]

How about fill them with expanding foam as well?

[MJNewton]

? To be honest I'm not exactly sure what my hesitation actually is! 

[SiBee]

I may have filled my bathroom window trickle with expanding fire foam. The howling gale blowing through the closed vent in the winter months from this exposed side seems to have been cured?

[Bitpipe]

If you're using expanding foam, get some isopropyl alcohol (ebay) and use it to clean as you go before it goes off. 

 

if doing more than one or two cans, get gun grade and a gun.

 

Wear gloves or you'll end up using sandpaper to get it off your skin.

 

Ask me how I know this

 

[MJNewton]

It sounds like we've been on the same training course! 

Edited May 22, 2019 by MJNewton

[Ferdinand]

As an intermediate, why not close them but use a bead of silicone around the edge of the shutter first, then wipe off the excess.

 

Then if you find it works OK with the MCHR and decide to foam it up in 1 or 2 years, you can reopen it with a modelling or Stanley knife and do the thing more thoroughly.

 

F

Edited May 22, 2019 by Ferdinand

[MJNewton]

Yes, I could try that. Thanks everyone for the comments - all food for thought and will help decide what to do. 

[Damian1658]

Has any body found any of the above methods effective at cutting out the noise. I specifically had acoustic laminate fitted to windows to cut out the noise of neighbours in the garden at night but now with legislation requiring trickle vents they just let noise in. Am trying to find a way to fill and sound proof those trickle vents. 

[Mungo]

Damian, we had a similar problem with road noise, and also have acoustic laminate (Planitherm). I removed the vents and cut strips of acoustic foam - slightly thicker than the vents so they expand once in place - then taped over the opening with white tape and refitted the vents. The noise has reduced and if needed, the foam can be easily removed.

It worked for us, especially as we had a few spare foam panels.

 

[mattman]

I filled all mine with 70% closed cell expanding foam (the slow expanding Soudal foam). I wanted 100% closed cell as more airtight but 70% was the closest I could find. For good measure I also put a bead of airtight soudal sealant on top of the foam. I then plan to put the trickle vent covers back on. In hindsight we should have got windows with no trickle vents but we ordered the windows early on before focusing on air tightness etc.