Cold draught from bathroom fan

[David W.E. Roberts]

Hi,

amazing what a change in the weather can bring.

Instead of worrying that the fan was not clearing hot air fast enough, I can now feel a cold draught coming in through the fan.

I have looked for an external vent which has a one way flap, but Screwfix at least do not seem to offer one.

I am also concerned that any such arrangement would require a reasonable positive pressure to open the vent, and so would cut down on the effeciency of the fan.

Is there a good one way valve for an extractor fan, or would you need powered (or cord activated) shutters on the fan body itself?

I can remeber the old VentAxia window fans where you pulled a cord and the shutters opened and the fan went on, and also have vague memories of powered versions which opened the shutters automatically.

Brrrr....soon be Christmas.

Dave R

[fred]

In article , David W.E. Roberts writes

Hopefully only when the fan is off :-)

You're getting a bit lazy mate, the check list in this group is always BES, TLC, Screwfix & then B&Q if desparate ;-)

Have a look at:

(white) (Terracotta) (Grey) I've got a similar design on a pretty wimpy ducted fan & it's ok.

It doesn't appear to be a problem on mine, the flaps are light and fall back by gravity (no springs). TLC also have one you can put in the duct:

I don't have experience of this type and don't know how the shutters close.

If you have a steady wind blowing onto the vent you might want to use an outlet with downward facing opening combined with the in-line backdraught shutter. Hopefully the downward facing outlet would catch the wind less. Sorry, no link for that one, but I have seen them in the wild, perhaps the sheds or builders' merchant.

Ah, those were the days . . . . . , now where's me tea, zzzzzzzzzzz . . . .

HTH

[MJ]

I got a Manrose fan for my downstairs toilet from TLC. It has shutters which automatically open but they're not very effective at keeping the cold out. Every winter I seal it up. It's also on a sheltered side of the house. It's a good fan for extraction though. Keeps all the toxic gases contained. You really feel the wind round your ankles when you're sat having a crap, and the toilet roll wafts around in the breeze.

I put a similar fan in the bathroom. Similar, because although it looks identical, on this one the shutters take a good few seconds to open after turning it on, and then slowly close on turning off. Don't know why they made it this way. Anyway, as the bathroom is south facing and direct in to most of the wind, I attached a right angle elbow of ducting to the outside of the house. It's of square section, about 8ins, galvanised steel and painted to blend in, with some deflectors inside to guide the air round the bend. I put some fine mesh in a frame and stuck it over the outlet, to keep birds and wasps from nesting, and spiders out. It works surprisingly well. Very little draught detectable, if any. I 'acquired' it from work when some contractors were in doing some air conditioning installation, so I can't help you locate any.

MJ