AndyF Posted October 26, 2012 Report Share Posted October 26, 2012 I'm planning to setup my workshop in a section of my unfinished basement which is roughly (L-shaped) 20' x 25' and 500 sq ft with 8' ceilings. It will be sealed off from the rest of the basement with a wall of plastic sheeting. There is one window in this section which is a typical basement bunker-sized window at 24" x 12". The gas water heater and gas furnace are in another section of the basement 25' away, but they are both direct vent without a flue. There are no air returns or vents in the shop. My dust collection isn't great, and as a result, I need to keep air in the shop from getting to the rest of the house. I'm thinking my best ventilation option might be to get one of those small window fans which have two fans side by side and mounting that in the window (somehow) when I'm working in the shop with the fans blowing to the outside and sucking air into the shop from the rest of the house. This would create some negative air pressure in the shop to prevent dust from escaping into the rest of the house. I'm wondering if small fans like this would have the power to do this though? Or maybe I should get a few of the larger model bathroom fans, drawing about 150 cfm each? Or do I need something else? Has anyone tried creating negative pressure in their shop to contain dust and provide ventilation? Other thoughts or suggestions on how to ventilate a basement shop? Quote Link to comment Share on other sites More sharing options...
Jfitz Posted October 26, 2012 Report Share Posted October 26, 2012 Hi Andy - Welcome. I have used the method you describe to creat a little negative pressure in my basement workshop - but for helping control the odor from finish, not for dust. I opened a few windows on the other (finished) side of the basement just a little, and it seemed to get enough of a draw to prevent odors from permeating the house. I don't see why it wouldn't at least help. I used this method when we were having some hardwood floors refinished, and it did a good job pulling the dust through and out the window. For dust control, you really should improve your DC and you might want to consider some sort of air cleaner. A good way to keep the house clean is to just not go back in forth with the dust and chips all over you and your shoes. 1 Quote Link to comment Share on other sites More sharing options...
duckkisser Posted October 26, 2012 Report Share Posted October 26, 2012 i would get a good air cleaner and mount it in the window like a air conditioner then it will draw it out and filter it at the same time. alot of those can draw 400 cfm because they are desighned for this issue in mind. a bathroom fan is ment to basicly suck out bad smells. 1 Quote Link to comment Share on other sites More sharing options...
CessnaPilotBarry Posted October 26, 2012 Report Share Posted October 26, 2012 Has anyone tried creating negative pressure in their shop to contain dust and provide ventilation? I do this with a 20" metal bladed round fan, found at Costco, to keep finishing smells out of the house that I share with the world's most sensitive to smells woman. I draw the air through a cat door in the basement door, and exhaust to the back yard through my back door. In the winter, I plug the area of the exit door opening around the fan with rigid blue foam, cut to fit. The foam parts are duct taped together and fold up when not in use. The plug is held in place in the doorway with plastic builder's shims. Notes: - My house has hydronic heat, so there are no air ducts in the basement. Negative pressure might mess with airflow, if you have HVAC ducts that are open to the shop area. - The open cat door does not allow enough makeup air to prevent downdrafting the furnace when the fan is on medium or high speeds and the plug is installed. Opening the (people) door 8 or more inches allows enough air. The cat door is fine with the fan on low. - I don't rely on this setup at all for dust control. Apples and oranges... - I don't like semi-permanent plastic sheets. That stuff is not hard to get burning, and it burns FAST. 2x4's and drywall are cheap, and it would not be difficult to install a temporary partition that is not a fire hazard. You don't even have to bother taping it. Overall, the negative pressure works GREAT to keep smells downstairs, even beer farts... 1 Quote Link to comment Share on other sites More sharing options...
mikem Posted October 26, 2012 Report Share Posted October 26, 2012 Do you have gas heat and/or hot water? If so, becareful with negative pressure. You could inadvertenly pull the carbon monoxide out of their chimneys and into the living area. 1 Quote Link to comment Share on other sites More sharing options...
Jfitz Posted October 29, 2012 Report Share Posted October 29, 2012 Good point about negative pressure and exhaust from water heaters or heating systems. I never had an issue as I always made sure to get enough make up air coming in so that both furnace and fan were ok, and the fan was so small it was really only able to prevent fumes from migrating up the stairs to the main house and not much more. We just replaced our systems with a high efficiency burner that pulls in combustion air from outside so no more worries about this at all so I might try to install a stronger fan. 1 Quote Link to comment Share on other sites More sharing options...
AndyF Posted October 30, 2012 Author Report Share Posted October 30, 2012 Thanks everyone. As suggested by CessnaPilotBarry, I've decided to skip the plastic sheet divider and build a real wall with an exterior door (for weatherstrip sealing) to separate the shop from the rest of the basement. I'm putting in 5/8" type X drywall for better noise control and fire-resistance. I purchased and hauled all of the materials for the wall down there on Sunday night with the wife's help. I also discovered that I can fit full 4x8 sheets through the basement door (there's a wall opposite the door, making me doubtful at first). I'll give a window fan a try first since that's the cheapest and easiest. Quote Link to comment Share on other sites More sharing options...
Jfitz Posted October 31, 2012 Report Share Posted October 31, 2012 Good luck with the wall. How about putting some outlets in there while you are at it? I put up a dividing wall between my shop and a storage area, to get some more wall space, and I ran several circuits of 110 and a feed of 220 - just in case. They come in handy. Quote Link to comment Share on other sites More sharing options...
AndyF Posted October 31, 2012 Author Report Share Posted October 31, 2012 Thanks John! The house electrical panel is in the shop. I'm going to put two temporary outlets right near the panel (one for tools, one for DC) for now. I'll remove them and do a full subpanel and circuits when I finish the shop entirely. I'll be running off extension cords until then, but I'm used to that in the garage. Also, forgot to reply to others above... I have gas heat and water, but they're both direct vent. The furnace draws intake air from outside. As suggested by Vic (thanks!), I'm going to put in a large Panasonic venting fan which pulls around 340 cfm. Quote Link to comment Share on other sites More sharing options...
sbarton22 Posted October 31, 2012 Report Share Posted October 31, 2012 +1 on the extra outlets. You can NEVER have enough outlets. I'm glad you are moving away from the plastic. Not only for the fire as mentioned, but plastic traps moisture, and in a basement, you are flirting with mold if you don't put plastic where it goes, and not all willy nilly (remember, concrete never fully cures and always accepts or releases moisture) If you are planning on opening your window, you could bring a different moisture content than what is comfortably set in your house (hot humid air in the summer, dry cold air in the winter). When you use plastic, it restricts dust and all that, but it also restricts moisture movement. There is a specific point where the moisture in the air wants to converts to water...called the dew point. If you are trapping the dew point somewhere unintended...boom..mold. Most residential construction is built so poorly that it actually becomes an advantage in that the house will breathe, letting moisture escape. However, there are places that won't happen, and you don't want to bring that on yourself. good luck! My suggestion is to save your nickels and when you can, upgrade your dust collection. It is REALLY worth it. 1 Quote Link to comment Share on other sites More sharing options...
Chris H Posted November 1, 2012 Report Share Posted November 1, 2012 Andy, I have a basement shop, and have done a few things similar to what you are talking about. I built a wall between the shop area and the "Furnace" area. This was to make sure saw dust stayed in the shop area. I did eventually put a make shift dust collection system in on the furnace side fo the wall, but it exhausts the air back to the shop side through a "Poor Man's Dust Box" (just sealed plywood box with exhaust air forced through 3 hepa filters). This keeps the noise tollerable, and the dust in one area. I also put in x2 high CFM bath fans in the shop that force the air into the same dust box. This does an amazing job of collecting the super fine dust. Because of geographic location, venting outside wasn't a good options for me. Too darn cold in the winter, and too hot/humid in the summers. Windows are also below grade, so water would be an issue too. Images are the dust box, easy, cheap, effective. Sorry the shop was messy when I took the pictures! No need to use insulated ducting for the vent fans, I just had it laying around from a bathroom remodel, so it got used. It is a pain to work with, so I reccomend just regular 4"-6" ducting depending on what your fan puts out. 1 Quote Link to comment Share on other sites More sharing options...
AndyF Posted November 1, 2012 Author Report Share Posted November 1, 2012 Good points about the plastic S Barton. Interesting and innovative idea on that dust box Chris. As many mentioned, I do really need to work on my dust collection. I just have a 1 HP Delta 600 cfm DC with 2 30 micron bags. In the garage, I often put it on the other side of a partially open garage door. I'm familiar with Bill Pentz's work, so I know that I'm probably better off just using my HEPA-filtered shop vac in the basement instead of this dust pump. Just to share my current line of thinking, I've been researching some, and I think I might get a 2 HP Grizzly DC and put a Thien baffle and Wynn filter on it. It's no ClearVue cyclone, but all of that will be about $550, which is more realistic for my current budget than a cyclone. Quote Link to comment Share on other sites More sharing options...
Vic Posted November 1, 2012 Report Share Posted November 1, 2012 Chris' approach would trump earlier recommendation from me, simply because it won't be messing wit house pressures as much. Good idea, Chris! Quote Link to comment Share on other sites More sharing options...
Chris H Posted November 29, 2012 Report Share Posted November 29, 2012 Thanks guys! One thing I didn't mention about the dust box that I have learned over time. Get 3 different Micron filters and install them progressively (lowest to highest). This saves a lot of money. The bottom filter in there is about $25 a pop. I only replace it about once every other year. The top two are more of the $5-$10 variety. They catch the big stuff so not to stress the expensive filter. I replace the cheap ones about 3-5 times a year. You can take them out of the box and just tap them off in the garbage (wearing a mask of course) and get a few more months out of each. 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.