Blowing dust outside from the basement

[Bob Weisner]

Hi:

Has anyone tried to set up their dust collection system so that the sawdust gets blown outside into some sort of box or container? I currently have my woodworking tools in my basement and have to haul the sawdust outside from the basement each time the dust bag gets full. I was thinking that there must be some way that the dust collector could blow the sawdust through a pipe or hose up and out of the basement and into a dust collection box that could be located outside of the house. Anyone have any suggestions as to how this could be made to work ?

Thanks,

Bob

[Steve Jenkins]

It can be done but the biggest downside is you are also blowing out all your heat or ac. You will need to put the collection area in a sealed box and make a filtered return. Pretty much a pain. Steve

[John Miliunas]

Bob, what Steve says may or may not be a consideration for you. I've heard of guys in year-round fair weather areas and, who live out in the country, just exhaust it straight out into an open catch area. Not pretty, but as long as nobody minds, no biggie. BUT, in your circumstance, besides the conditioned air being lost, another consideration is, where will the DC be drawing the air *from*? What I mean by that is, if you're located in a basement, is there the chance that you have fuel-fired heating and/or hot water? If so, those DC's have enough capacity to move, and therefore, *pull* a lot of air. Some of that air could easily be some of the spent gases from a fuel-fired source! NOT a good thing! Having the sawdust blown into an area outside your workspace is a fine idea, but if the above conditions are present, you'll want to equalize the air pressure by bringing the filtered exhaust air back into the shop.

[Keith Outten]

Bud,

My dust collector is setup as you describe with a direct dump outside. I live in a rural area with a four acre back yard and I prefer the direct dump method. The loss of conditioned air isn't as big a problem as you would think, at least not in Virginia.

The performance boost of not having any restriction is like having a larger DC, and the air in my shop is cleaner as I don't have to worry about filters. I have a heat pump system and it will run a little longer when the DC is running but not excessively. If you consider the production time that is not lost emptying bags it is a bonus. Fine dust disapears, large chips from my planer end up in a pile and I spread them over my back yard, except of course walnut.

I also have an upstairs office where my Laser Engraver is located and it is tied into my shop dust collection system. My office space is very small, less than 600 square feet and I do notice the drop in temperature when I engrave a long duration project...over an hour. When this happens my heat pump will definately run a little longer than normal.

Ten years ago I lived in a residential neighborhood and I built a 400 gallon plywood box to catch the effluent. I installed roof vents on the top of the box and stapled baby diapers beneath the vents as filters. This system worked very well, in fact since I had to dispose of the chips I found a horse stable nearby that purchased the chips from me at $5 per 30 gallon can. I used to laugh at the fact that my workshop had almost no waste....I even sold the dust off of the floor

[John Miliunas]

Keith, that's a "success story" if ever I heard one and, if a guy can successfully pull that off, that's awesome. I'm simply going by my own personal experience. When I set up my DC system in the new shop, I originally just had the venting side of the Woodsucker open. I figured that with it being out in the garage and the garage being insulated, my conditioned air would not be completely "wasted". BUT, at the time, I had a woodburner in the shop and, when I fired up the DC, after about 5 or 10 minutes, I'd start to get smoke coming back into the shop! It was actually pulling spent gases back through instead of up the flu. The woodburner is now gone and a Hot Dawg in its place. But, my exhaust is now recirculated back into the shop for the same reason(s). Heck, before I did the loop back into the shop, with the DC running, you'd even have a heckuva' time pushing the door into the garage open! There was literally a LOT of negative pressure working on it! FWIW, in a basement situation, I'm not sure I'd want to take a chance on it. On the other hand, I don't know Bob's location on the globe. Maybe he's in a temperate area where he could keep a window open, thus equalizing everything and not worry about losing conditioned air or pulling vent gas back through the area. Just something to think about and consider...

[Bob Weisner]

Hi:

I forgot to mention that I also have a Bilco trap door to get in and out of the basement. If I opened the trap door, would that help equalize the air pressure in the basement? There is some gas fired equipment in the basement. 1. Natural gas hot water heaters . 2. Natural gas hot water boiler. The hot water heaters are vented straight up to the roof . The boiler is vented up and out to the side of the house. Also, would it be necessary to open both trap doors or would one be enough to equalize the air pressure?

Thanks,

Bob

[John Miliunas]

Bob, I isn't no engineer (can hardly spell it, much less be one!), but I would venture a guess that yes, that would probably take care of it. I guess what I would do is try to place the DC in a spot where, if you *needed* to, you could still route filtered air back into the basement. Then, just try it.

Hopefully, one of our more knowledgeable members will chime in, but I think there are just too many variables involved to give a pat answer. There's the cfm of the DC, your duct size, the cubic feet of your area, the proximity of the gas-fired appliances, sources of fresh air, bla...bla-bla, bla...

In my instance, it was totally "seat of the pants" engineering. I thought I could just exhaust into the garage and there would be enough air infiltration back through the cracks in the doors and such to not be a problem. Plus, it's a fairly decent sized shop with pretty high ceilings. I figured it would take quite a bit to pull the air outta' there! Wrong answer! Hence, the re-route back into the shop. Good luck with whichever way you end up doing it. In the meantime, I hope one of our more mathematically proficient members jumps in here to bail me out!

[Bob Weisner]

John:

Thanks for the information. The basement is unheated except for some heat radiating off of the pipes from the hot water boiler, it is really too cold to do any woodworking in the basement. In the winter I might spend an hour doing woodworking. After that, the cold starts to set in. Where I live, the temperature has gotten down to as low as 21 degrees below zero. The spring , summer and part of the fall is when I do the majority of my woodworking. At that time of the year, I can open not only the Bilco doors, but all of the basement windows. When I have the basement windows open it is like a fan in the basement sometimes.

Bob

[Keith Outten]

I'll admit that I've never had a workshop that was that tight a space. I've always had at least one garage door and they will automatically provide enough leakage to account for the DC discharge. I would imagine that cracking a window would do the trick, consider that the DC piping is only 4" diameter, a hole of the same circumference would provide the necessary vent size. A 1/4" crack at a window sill would be large enough I would think.

Consider that my very old 1.5 hp Grizzly DC will pull a sufficient flow across my 24" dual drum sander at the opposite end of my 36 foot long workshop. No dust in the air from the sander at all and my 4" DC piping drops down from a 10 foot ceiling. I'm in the same boat as you John, I can't substantiate my system with numbers or engineering data...I just know that it works

When I purchased my Dust Collector about 12 years ago I used the bags for about 3 months and hated them. No matter what I have to do I will never use a bag or filter inside my workshop again, the mess and the noise and the problems of dumping chips are not an option for me. Note I am not looking for a larger DC system, don't need 3 hp or 6" diameter pipe, the solution for me was to reduce the restriction in my system by getting rid of the inside filter.

This isn't a recommendation, my system works for me but may not be a suitable solution for anyone else.