Since we seam to be on this dust collection kick I thought I would add another one

[John Cooper2]

On another thread I talked about how I picked up a monster squirrel cage blower and had intended to use it as a down draft table, well that idea has evolved and I am no longer going to use the blower for that.

Someone suggested that I make a overhead air filter from the blower and that sent light bulbs a flashing, well at least glowing a little.

I know this will not work for most people but I think it will for me so I want to put it out there and see if I can get steered in another direction.

My 18' x 32' shop in located in Northern California and while it does get real hot 110 and real cold 28 at times I would say that 90% of the time it is very nice and comfortable to work in my detached shop. I have no heating or AC, just some fans to blow when it really gets hot, like today. There is a 10' wide opening (one day it may have a door) and a 36" man door on another wall, so it is not air tight by any means.

To my point.

What if I mounted the monster fan outside and ducted the air from it to the center of my shop.

To me the point of a overhead air filter is to clean the air, so if I just bring in air from outside that is not full of dust I would be doing the same thing, If not better.

Would not have to worry about clogged filters, can wire it up with a timer so I could let it run after I leave.

Have the fan, it cost me $10.00 or so. The expense would be in the 18' or feet of duct work. Have a great sheetmetal shop in our little town so they could fab it pretty easy.

Please let me know you thoughts.

[Jim Neeley]

John,

Great idea, except I'd use the fan to exhaust the air rather than supply it. When you blow air high velocity into the room you tend to stir things up. When you exhaust it in one place and little bits leak in from all over it'll be moving more slowly in the shop so should stir less dust.

Just my $0.02...

[John Cooper2]

True,

I plugged it in today and had to leave the shop for awhile it kicked up so much dust.

One thought for having it blow in was I could use it as a cooling fan as well.

Very early in planning, thanks for the thoughts.

[Michael W. Clark]

I tend to agree with Jim, I think you would be better off exhausting. However, if you want cooling air, you should duct the outlet to something to get better air distribution and lower the velocity. They make "duct socks" for supply air systems that are basically a plastic bag with holes in it. I don't think they look good, but the same concept could be done with ductwork or a plywood box used as a plenum. Probably better to use sheetmetal in case you get moisture in the air that could cause mildew on the plywood.

Mike

[Ryan Brucks]

Also consider weather it is attached to a house or not.

With your 1st plan, you are putting the garage under positive pressure. Now when you open the garage door to the house, much more dusty air will be pushed into the house. It doesn't take much for the small particle count to skyrocket. Note that some people make their main house positive on purpose so they get no unfiltered infiltration... but that would be doing the opposite in this case to your house. you'd essentially be making the house negative relative to the garage (ignoring other sources of air coming/going from the house for a moment).

On the other hand, if you have it blow out like everyone said, the room will be under negative pressure and when the door is opened, there should be much less air mixing since air will suck into the garage from the house (of course if you open the door really fast you will mix more air... open the door gently if the air is bad).

just something to consider.

*edit* saw the word Detached in the OP... so my info is moot in this case

[John Cooper2]

Yes it is detached and has a 10' wide opening plus a 36" door that pretty much open all the time so it's pretty much a open air shop. In the winter I may hang a tarp over the big opening and close the door, but it's far from air tight. The exhaust from the DC is just blown out the back.

My thought process was that if there is enough new air coming in then any suspended dust would be pushed out fairly quick with this big blower. I can see where it might be better to suck everything out, but then I would loose my "cooling effect". Not sure if using it as exhaust has enough benefits to outweigh the cooling effect in the summer time.

[Jim Neeley]

If your DC is exhausted outside it is, in effect, a room air "cleaner", just like the fan would be, albeit noisy and not as efficient.

[Carl Beckett]

If you exhaust it to the outside, then that air gets 'made up' from somewhere - ie the outside. So you are pulling in outside air the entire time. Hence the same cooling effect?

But if you are wanting the motion of the air to provide the cooling effect, then blowing it right down on you works. I wouldnt worry too much about dust getting stirred up, because once the initial purge is done then after that its all the same (if you run it regularly that is). In fact, one way I clean my shop is to turn on a large industrial fan I have - blowing out the door - and then use the leaf blower (electric one) to blow out the entire shop which then gets pushed right out the over head door opening.

If Im doing a lot of sanding I like to do it outdoors, with a fan blowing across the work area to take the dust with it.

Another option might be a 'swamp cooler' if your climate is dry. Set it up to blow across a moist surface (bales of hay or something like this) so there is evaporation happening as the air blows across it.

(and great tips for those with attached spaces - I balance various parts of my house to control relative pressure between spaces - such as a crawl space and garage, so migration is in the direction I want)

Net is: +1 on suggestion to blow out , not in.

[John Cooper2]

Because of the noise factor I could see this blower running much more than the DC. DC is really only going to run for short periods of time. I could see running this most of the time that I am in the shop, especially in the warmer months.

[Aaron Berk]

I recently just quit using this method that your speaking of.
I had a fan outside the back door on the stoop, and I would open the door and flush air through my shop and out the roll up garage door.

Having a flow to the air made it pretty efficient at keeping the dust on the move out the door.
Your idea sounds good, but where is the air to go? Are you just going to dump it towards the floor and let it swirl around and find it's own exit?

Cross ventilation is a PROVEN method of exhausting contaminated air. So you CAN make it work for you.




So I quit using it though, it was a big hassle. And it's not always feasible to open doors and cross vent the shop (rainy days, 200 degree days, wee hrs of the night). I suppose though if I had invested the time to create an HVAC style system and used some type of shuttered exhaust port (like a gable vent fan) then it would have worked for me for awhile longer. I'm happier now with my AC and 78degree shop though

[marty shultz]

I agree with using the fan to exhaust the air from your shop. Blown dust has a very random flight path and I believe you will have more airborne dust by blowing air int the shop.