Extraction fan for home workshop?

[Tiggy_dorset]

A quick pick of your brains....

i was grinding off galv from some sheet tonight in the workshop and thought about extraction. What is the recommended/suitable cfm or m3/h rating for an in line duct extraction fan for an 8ft x 12ft area. I have been looking at hydroponic sites and am considering a 550m3/h for my needs.

Cheers guys.

P.s. I plan to make a funnel for the end of the duct so I can move it around and hang from the ceiling above a work area

 

[cumbriasteve]

A 550 would be rated at approx 18 air changes an hour over the workshop volume if its about 2.5 metres high, the trouble is I don't know if thats a good or bad rating and then there is the different 'mass' between grind particles and fumes to consider.

When I was daft enough to grind mill scale off my steel in the workshop using flapwheels, I had doors open both ends with a gale blowing through but the black particle dust was still settling everywhere and my mask went black within minutes.

I have seen a small bathroom xpelair thingy attached to a home made hood ( made from oil cans) and 6" flexi ducting used to remove welding fumes and it worked great although was localised to the weld area of course.

 

[Tiggy_dorset]

I have double doors that I normally keep open, which is not bad for air flow. Sometimes though I have to consider neighbours and close the doors when Im being overly noisy. This is when extraction becomes important.

I guess there is an insurnace/health and safety figure for workplaces, as a few years ago we occasionally had a guy come round testing the extraction flow rates. The figure can't be huge because they used to pass the tests whilst I thought the extraction in that place was pants.

I might just go for the biggest suction I can afford

 

[cumbriasteve]

I might just go for the biggest suction I can afford

Theres no answer to that

 

[Rick]

The problem is the Mass of the particles. To simply "change the air" won't do enough. You'll need a HUGE extractor to do anything remotely useful IMO.

 

[Tiggy_dorset]

Looking at this one.
http://www.ebay.co.uk/itm/Hydroponi...arden_PlantsSeedsBulbs_JN&hash=item2eb683a87e

Seems a good price for the size.

 

[harvey639]

i have suspended an old kitchen hood over the general area where i weld and run a duct out to the window. works fairly well and it didnt cost me a thing

 

[Tiggy_dorset]

i have suspended an old kitchen hood over the general area where i weld and run a duct out to the window. works fairly well and it didnt cost me a thing

I hope the missus didnt notice something missing from the kitchen.... or do you do your welding on the cooker?

 

[Tiggy_dorset]

I was planning to use a vacuum cleaner for dust extraction of my sandblasting cabinet (an unfinished project I will be getting back to very soon). My thought now is to buy the fan and have a movable duct around the workshop, with a seperate take off specifically for the blast cabinet. Kill 2 birds with one stone

Ill order it later on.

 

[harvey639]

i was given the hood by a friend who was replacing his for a bigger one.