Extractor fan

[HowardM]

I have been looking for an extractor fan to get rid of the fin dust made by the big saw. I don’t care about filtering to retain heat. What size do you think for my shed, 7x7x4metres.?
My shed is multi function, not just for woodworking., hence the haphazard layout, storage is under review.

 

[Sideways]

Download a catalogue from ebm-papst.
200m3 volume.
Say 10 air changes an hour to replace all the air every 6 minutes.
2000 cubic m/h
You probably need an axial plate fan, 300mm dia and 100Watts minimum.

For a fan to work at max you need plenty of holes for the air to get in too.
I might be tempted to go a size up to a 350mm fan.
Think about weatherproofing / louvres / rust resistant materials if it's going to sit in the wall all the time. Otherwise pretty similar fans are used for commercial kitchen fume extraction.

 

[Jameshow]

Download a catalogue from ebm-papst.
200m3 volume.
Say 10 air changes an hour to replace all the air every 6 minutes.
2000 cubic m/h
You probably need an axial plate fan, 300mm dia and 100Watts minimum.

For a fan to work at max you need plenty of holes for the air to get in too.
I might be tempted to go a size up to a 350mm fan.
Think about weatherproofing / louvres / rust resistant materials if it's going to sit in the wall all the time. Otherwise pretty similar fans are used for commercial kitchen fume extraction.

100w not more??

 

[Sideways]

A quick google gave me a 300mm / 100W plate fan with about 2050m3/h so that seemed like a spec to suggest as a minimum.
355mm, 400mm, 500mm dia fans increase the airflow progressively to over 5000m3/h and motor power tends to go up with size...
These things move a lot of free air but don't generate much pressure. It's important that the replacement air can get in easily

 

[HowardM]

Thanks very much.
Once one has the correct search words one gets relevant results, rather than bathroom extractors

 

[Jones]

An open door or window could work better for free.

 

[Tony51]

I would fit a non return damper. Keep out cold winds and unwanted wasps. This will affect the air flow but not by much.Going up a size would overcome this and any Louvre you fit.
Tony

 

[Agent_zed]

An open door or window could work better for free.

only if there is a cross breeze. If the outside air isn't a different temperature or moving, there is no reason for the air in your shed to decide to move from one place to the next. Even outside on a windless day the dust will hang in the air around where you are working.