bathroom extractor fan not doing its job

[ajsoad]

hi all. just finished fitting my new bathroom and for some reason the extractor fan isnt extracting enough of the steam out. the bathroom is only 2.7m x 1.9m. ive got this http://www.****************/shop/Electrical//100mm+Low+Profile+Extractor+Fan+Timer/d/sd/p71737 fan fitted and ive turned the dial to the maximum on it. the red square shows the position of the fan. also there is a trickle vent on the window. ive also tried removing the pipe from the extractor fan to check if it was restricting the flow but didnt make a diffrence. any ideas? or have i just bought a useless fan? details for the fan are

• IPX4, 220-240V 20W
• Wall or Ceiling Mounted only
• Part F Compliant
• Backdraught Shutter
• Airflow: 90m3/h, 25l/s
• Sound : 38dBA @3m.

 

[ajsoad]

just noticed the link wont work. i got it from toolstation. item no 71737

 

[marvoni]

Either it's a useless fan or the room is so well sealed that replacement (make-up) air can't get in.

Try a mixed flow fan, they're quieter, more efficient, better pressure handling etc.

 

[Phil]

We have a 9 inch kitchen fan in our bathroom, never rated those poxy 4 inch fans.

Clears the room a treat and will hold up a sheet of A4.

 

[PlumbBobBob]

have you tested it with a piece of toilet paper? turn it on and put a piece on the face if it stays in place it is working maybe you are making too much steam?

 

[ajsoad]

no havent yet tried any paper on it. if getting the make up air is the problem what options would i have to sort that? dont really want to take any more off the door as ive taken more than the allowed 10mm off the bottom as it is. thanx

 

[marvoni]

Well it's easy to test if make-up air is the issue, you'll notice a big performance improvement when the bathroom door is open. If it is a problem you could cut a hole in the bathroom door and install a stainless steel or anodized aluminum louver.