4" Extrator and ducting

[TrichomeUK]

JOOLZ: "It is quite big, but the ducting gives the impression that some huge industrial unit is hiding in the attic"

6 inchers are babies m8, you haven't seen anything yet!

All the best

[OMH]

have you ever seen the 12" ones?

You need a silencer for them, and the first time i fired one up in a room I did, the suction actually snapped some of the batoning that was holding the BWB sheeting to the roof beams. No mean feat on a room that was 20" x 8". It seriously scared me It was like a bloody jet engine

The 6" inline radial fans are spot on mate. I use a 6" for extraction and a 4" for an air in, and take the air input ducting straight onto the back of an oscillating fan, pointed at my babies.

Hang em up in the loft from a eyelet screw, with bungie cords to deaden the vibration, and you will never know its there.

Another thing about those fans - they are much more efficient at sucking than they are at blowing, so its much better to have the fan a fair distance from the room, so you have a shorter bit of ducting for your exhaust. The opposite applies for it you are using them as an air in fan.

Also - you get better efficiency from the fans if you don't take an output air line downwards, and an air in line upwards. Hot air rises, so if the ducting goes downwards, the fan is having to fight against the way the air naturally wants to move - vice versa with cold air. Keeping the ducting as straight as possible also will help with the fans efficiency.

I know this is mostly common sense, but hey, if someone finds it useful.....