Duct And Terminal For 6" Ceiling Fan.

[securespark]

Just had one fitted to a flat warm roof, and the roofer said he had fitted a flue terminal to the end of the pipe.

I said that would mean there would be no flyscreen. He said that won't be a problem as any critters getting in would be swiftly evicted when the fan came on.

Surely there's a proper kit for venting through a flat warm roof with an insect-proof terminal?

 

[Wayners]

Industrial fans have paper filters

Domestic have a flap that stops cold air blowing through when not in use.

 

[securespark]

It's supposed to have flaps, but it doesn't seem to stop air blowing through.
The blades spin when the fan is off.

And I can see light through the duct.

The flaps, if they close, may stop insects getting in the room, but surely it would be better if the flue terminal stopped insect ingress.

Even gravity flaps stop them getting in when the fan is off.