WOODWORKING QUIZ for 18 Oct 04

[Ralph Jones]

Good Evening Friends,
I am getting ready to make a dust collector for my shop which is 20' x 24' x 8' and I plan to recycle the air 8 times in an hour. What size motor/fan should I buy to achieve the correct amount of CFM for the job?

Respectfully,

[fxst]

bloody big one

[Toggy]

Open the doors each end & let the wind blow through. No recycle; just clean fresh air.

Ken

[Sturdee]

I am getting ready to make a dust collector for my shop which is 20' x 24' x 8' and I plan to recycle the air 8 times in an hour. What size motor/fan should I buy to achieve the correct amount of CFM for the job?

Are you making a dust collector or a room air filter because the specs of workshop size and number of air changes is not relevant to a dust collector.


Peter.

[Wood Borer]

512?

[echnidna]

Ralph,
Most of Oz has a fabulous climate compared to the US.
We dont have to shovel snow, our lakes and rivers don't freeze over.
So we dont spend oodles heating our workshops.
If we want to ensure a steady air change we can work with windows and doors open or even fit a couple of kitchen type exhaust fans to get rid of the airborne dust in our workshop atmoshere.

[lyctus]

You are wanting to filter a volume of 3,840 cubic feet 8 times in an hour. With a furnace type fan you can expect to do this with a 1/4hp motor no problem. I would suggest a bigger motor/fan combination to say 1/2hp with a medium size furnace fan and filter the air, say more like 15-20 times per hour.

[Ralph Jones]

Good Evening Friends,
Great responses friends, the one who suggested 512 CFM is correct, I think it was Bob Wilson. However the furnace fan/motor I bought for $30.00 dollars from my HVAC friend, informed me that it would recycle the air considerably more than what the formula calls for. I also ordered a filter from him that when it is full all I have to do is wash it out and replace in the case. unfortunately it cost $100.00.

You fellows are luck that you don't have to worry about the changing weather like we do, I'll bet you don't even have snow blowers down there.

Thank you all for your support.

Respectfully,

[Wood Borer]

You are correct Ralph, not much snow here and snow blowers are not heard of.