Having recently moved into current property, needed to change the '99 fans for something more efficient, so, backdraught flaps were on the list
Excellent does what it says on the tin 👍
Really good fan does the job perfectly we have just noticed after about a week of fitting it it seems to of created a rattle nothing obvious as everything is tight but just seems a little bit more noisier than when first fitted.
We replaced an old ventaxia model with one of these and unfortunately we can really feel the cold draught from it. So much so that we've ended up turning it off much of the time. Our heating now has to work much harder if we leave it on during the colder part of the day. It's also considerably noisier, another reason we turn it off much of the time.