Putting a DC outside.

[Bob Feeser]

I know a guy who has a leaf blower stuck in the wall of his shop, and that is attached to his DC 6" tubing system in his shop. Wood chips, sawdust, etc are not challenge. He just vents it into a lean to outside room. Unfortunately leaf blowers are not designed for continual use, so he has to replace them periodically.

Pertaining to venting outside with a dust collection system, I wish I could do that, but my neighbors are too close. I do have some input though. My shop is in the basement, which is completely finished. A separate room houses the heat pump, natural gas backup furnace, forced air. In the shop I have a salamander 55,000 btu kerosene heater. I do not leave the vents open to heat the shop during the winter. When I go down there to work, I turn on the kero blast heater for about 10 minutes, with everythng closed up, with me not in the room. The room, the tools, and everything gets heated up real well. Then I enter the room, and open a window and put a fan in it, and open a window on the other side of the shop a little. So I have a clean air flow. Dust easily exits the room. The kero blast heater is hooked to a thermostat which I keep set at 70 degrees. When the air cools down, it automatically kicks on. If I am done creating dust for a while, let's say for glue up, I close both the windows, and open the regular forced air heating vents, for clean air heat. It works great.
Pertaining to the CO2 concerns, I do have a natural gas water heater as well in the furnace room. That room is sealed from the shop, even in the ceiling, although it breathes from the room alongside it, which is also sealed from the shop. In plain words, air is not being drawn out of the furnace room, and positive air flow is possible because this home was built in the 50's and has the 3/4' stips keeping the cinderblock walls off of the plaster board sheets. So the walls breath all the way through to the attic, which has sophit vents. The whole system works beautifully.
I know others will suggest the propane heaters of the type I am talking about, rather than kerosene, and even more will say use the ceiling radiating models, but the kero unit works well for me. When the air is changing, the cone gets red hot, and it burns the fuel so efficiently, that you don't really smell anything, and the fresh air change is so frequent, it doesn't matter much anyhow.
My dust collector is a Dust Force with large bags, that is located right next to the venting window that the fan is in. Even those .5 micron bags are spewing ultra fine particles in the air, so when I do not have a fan in the window, my mask is on. I still wish I had an outside dust collection system, with a lean to room. That would be great.
By the way I have an off timer hooked up to the kero blast heater, so if the thermostat kicks it off, and I forget it is on, the timer expires, and prevents it from going on when I am not there. That is important, a heater of this type, running out of fuel, running sporadically, is a challenge, even with a detector built in to prevent restarts when there isn't a flame.

[Tim Marks]

I know others will suggest the propane heaters of the type I am talking about, rather than kerosene, and even more will say use the ceiling radiating models, but the kero unit works well for me.

Using an unvented propane heater will put an incredibel amount of moisture into the air. Once the room cools back down, it will probably condense out of the air. Maybe not a good idea when you have alot iron machienry that rusts.... kerosene is a better choice, since it will act to dry the air in the room instead of make it more humid.

Keep an eye on the expiration date on your CO alarm... they don't last forever.

[Bob Feeser]

Using an unvented propane heater will put an incredibel amount of moisture into the air. Once the room cools back down, it will probably condense out of the air. Maybe not a good idea when you have alot iron machienry that rusts.... kerosene is a better choice, since it will act to dry the air in the room instead of make it more humid.

Keep an eye on the expiration date on your CO alarm... they don't last forever.

Tim,
Thanks for the tip. I am no longer sorry that I didn't buy propane instead. I do have a natural gas wall unit out on the Veranda/greenhouse addition, that I rarely have to turn on, and that does create moisture just like you spoke of condensing on the glass windows.

[David Giles]

Now that Bill has moved into calculus territory with his heat loss mathematics, we need to add in the heat generated by cutting wood. The dust collector wouldn't be on unless another machine was in use. And all of the energy from the table saw ultimately ends up as heat from friction. So what is the temperature gain from 6-12 amps at 220V being pulled from the table saw or jointer?

[Chase Gregory]

Unless you designed some pretty comprehensive airflow into your shop you cannot exchange all of that air in any short amount of time - it's an exponential process even w/ HVAC systems - you exchange some of it repeatedly.

The DC will pull a relatively narrow path through the room, if it's even a traceable path, via a point source. So it is a very inefficient means to exchange the air or affect the room temperature.

Some of the closest air to the DC inlets is warmed by motors and operators.

Just design your makeup air to filter in through a network of 500w incadescent fixtures.... You won't need to add any more heat than that!

Chaser

[Ben Grunow]

Bill, we routinely install systems in the houses we build that allow the air exhausted by a kitchen hood to be replace with heated air that is drawn in through a fresh air intake and heated prior to being blown into the living space. My understanding is that the HVAC guys are just trying to match the cfm (up to the highest rating on the air handler/furnace blower) of the exhaust fan to try to replace the air being exhausted at the same rate.

That said, it seems to me that this is probably overkill as the heat loss is slower (as you say) and less immediate. I think the more important factor is the overall pressure within a house as there is potential to backdraft heating sources and fireplaces and I have even seen a kitchen where the door is very difficult to open when the hood is on full power.

My shop DC exhausts outside and I froze today after running it for half an hour of router table work. I plan to bring the exhaust in asap. It is a waste of energy in a cold climate.

[Steve Clardy]

My 4hp unit is outside on a concrete pad.
I don't run bags. I just blow it into a pile outside.

[Bill Pentz]

My 4hp unit is outside on a concrete pad.
I don't run bags. I just blow it into a pile outside.

I’m with Steve on this. After we work all the numbers, add in for heat generated by our tools and compensate for the dust collection basically creating a circle of air, the bottom line is there is really not that much heat lost, particularly if you only run your dust collector while making wood dust. I seriously doubt that running my cyclone full out while working in my shop on a 20 degree day outside would come close to what my health insurance and I pay for my breathing treatments, supplemental oxygen, sprays, and pills.

The issue with getting rid of the fine dust is just like getting rid of the heat. A good sized exhaust fan or even large air cleaner is just not going to get rid of enough of the fine dust fast enough to keep from failing an air quality test.

Worse, because the dust we miss collecting tends to stick around for months to years and is easily launched airborne again and again by airflows in our shops, those who have poor fine dust collection quickly build up dangerously unhealthy amounts of fine air borne dust. By venting outside we don’t fix the collection problems but at least reduce this dangerously high buildup of the fine invisible dust.

bill

[Johnathan Bussom]

Is locating the DC unit outside of the shop walls a particular problem?

Anyone running thier DC outboard?

Chaser

Chaser,
My shop consists of a one car garage, I built an addition on the side specifically to hold my DC and air compressor, I have a Grizzly 1029 DC wired 220 with a remote switch inside the shop, outside the addition I have 2 55gal plastic drums stacked that collect 98% of the dust/chips before it gets to the dc, the bags on the dc only need checked/cleaned about once for every 4 times I remove 55 gal of chips from the outside bottom barrel. Unless something comes undone I seldom get any dust in the shed (as I call it) but it has happened once.

Noise, I am glad it is outside, I turn it on and hear the startup and know it is working, then I turn on whatever I am using which drowns out the DC quickly. My biggest problem in the winter with the DC is that I don't use it lest I have several pieces to cut/plane/route/turn

John