Is This Some Kind Of Backdraught Shutter?

[securespark]

I've just bought an Envirovent Silent 100T fan.

As usual with modern stuff (I'm making myself sound a real old git now), the instructions are absolute pants.

There's a piece of paper implying that you throw away two items attached to the fan (a cardboard insert at the back and a foam spacer under the grille, but there is nothing showing you (or telling you in the instructions) what the very thin transparent disc of plastic is at the back of the fan. It appears to be deliberately (but at the same time quite flimsily) attached to two plastic nipples.

So is it some kind of shutter?

If so, I can't quite believe that things are getting so cheap and nasty!

 

[JohnW2]

.... There's a piece of paper implying that you throw away two items attached to the fan (a cardboard insert at the back and a foam spacer under the grille, but there is nothing showing you (or telling you in the instructions) what the very thin transparent disc of plastic is at the back of the fan. It appears to be deliberately (but at the same time quite flimsily) attached to two plastic nipples.

If that disk is not very flimsy, it's just going to obstruct airflow (in both directions), isn't it? Are you sure you weren't meant to throw it out as well as the cardboard?

 

[sparkwright]

I think it's the back draught shutter.

 

[flameport]

very thin transparent disc of plastic

It's their feeble attempt at a backdraught shutter.

Best removed and disposed of as if left in, it will very quickly get clogged with dirt and you will just end up removing it anyway.

 

[securespark]

Thanks, people.

I think I'll get rid. It does seem ridiculously insubstantial.