Shop ventilation

While cruising craigslist for a cheap welding fume extractor (I saw 20 year old one for $1700) I had a flash idea of making my own with some materials I had on hand (there's a long line of those projects). Then had the thought that I already have a suction fan in the shop in the form of the shop vac. A couple years ago I found an idea on the web and I modified my shop vac to sit on a 5 gal bucket so the oil and chips fall into the bucket while the filter stays relatively clean above the bucket the intake hose goes into. I have ordered activated charcoal filters from Amazon to fit in the top portion of the vacuum and will report back on how well it works, or not. The vac is too loud for prolonged use but will effect a decent, ready made suction and filter to see if the charcoal filters clean the smokey, oily air...
 
I have seen several good quality inline fans while searching for hydroponic supplies. Most of them are available in a number of diameters up to 12 inches I think and are designed for continuous use. I can't remember the CFM's but they are used to keep circulating fresh air in room sized growing systems. They also have the inline carbon filters to reduce airborne pathogens and smells so the should also work for cleaning the air up quite nicely. So have a look at some different hydro sites and see if they don't have what you are looking for.

Bob
 
Last edited:
Thanks Bob, will check it out. The carbon filters from amazon should be here early next week.
 
Just an update, the carbon filter pads came today. I'm not sure I'll have the chance to test them out before next week.

Why does USPS call it tracking when it's not? Jeesh, their system is really inadequate compared to the competition.
 
I am using a Squirrel cage Stove exhaust to vent. I am not sure on the exact cfm but it is about 3 to 4 times more than a typical bathroom exhaust. If I would have to guess it is pushing 300 cfm. It can also be outfitted with a filter instead of venting outside.

The noise is actually less than a bathroom exhaust.
 
I'm building a propane foundry to do some blacksmithing. A friend of mine has been using his to make knives for years. His setup is in his garage. He opens the garage doors. When I read the instructions on the propane regulator, it specifically says not to operate in any condition with an overhead roof or ceiling even if doors are open etc. Says it must be outside; which is pretty frigid this time of year!

Any incites apprec
 
I did a bunch of MIG welding recently in my garage shop, I opened the garage doors and used a 'high velocity' fan I purchased at my local Wilco Farm store. I set it on a mobile work table about 30 inches high near the welding table and aimed it out the door. Its an all steel fan and they are not kidding about high velocity at its lowest speed its like an airplane propeller WHAAAAHH. There wasn't even a hint of smoke in the garage it really moves some air. Under $40.

http://www.drillspot.com/products/574668/lakewood_engineering_and_mfg_1134wp_wp_18_hi_velocity_fan
 
thanks; I get cold thinking about a fan this time of year; another month or so and I'll start the foundry.
 
I am in the process of setting up my basement shop which will be for machining tasks only. All welding, heat treating, and (hopefully) eventual foundry work gets done in the garage with the doors open. Just the same, some sort of ventilation will be required for the basement shop for those pesky projects that get a little smoky when cutting from time to time or when doing some soldering or silver soldering. I initially considered just using a bathroom fan ducted out the side of the house. I don't mind if it takes a couple of minutes to clear the air, but if it takes too long, it would be no good. I also thought about using a small squirrel cage blower with a 2" or 3" hose positioned near the smoke source, using it only when necessary. Any thoughts anyone?
 
KevinD,
In my line of work, we work with engineered ventilation systems quite a lot. Here is a very simple solution that may work for your problem. Your friendly neighborhood shop vac. If you place the open suction end of the 2" hose within approximately 2" of where the smoke is being generated, that will put the smoke in the capture zone of the shop vacs suction, and the gross majority will be sucked into the hose. The majority of the smoke is particulate, and the normal vacuum filter will remove most of it from the air. I would use one of the pleated paper filters with the foam sleeve over that. It is not nearly as efficient as a HEPA filter, but it will do a very good job of capturing the majority of the smoke particles. A better system would be an inline HEPA filter to a separate suction (blower), but for limited use, the vacuum will work fine. Yes, I know the shop vac is not the best solution, but I would bet money that you already have one, and could fab up some sort of mounting for the hose suction. You can also make a flattened funnel looking device to attach to the vacs suction to enlarge the capture zone. In normal HEPA ventilated systems, we design for an approximate 100-125 LFM of flow across the work opening to ensure adequate capture of airborne particulate.

There are a number of companies who specialize in the design of ventilation systems. Do a web search on HEPA ventilation, and you should be able to find enough information to fabricate your owns system that is quite effective.

Mitch
 
Back
Top