migsie

I am building a home garage where I plan to pursue my car audio and woodworking hobbies. Off the bat, I am putting in a table saw w/ shop vac attachment, drill press, router table, vent hood and chemical cabinet. In the years to come I may add a scroll saw, and an air-compressor to spray glue, paint, etc, as well as run a collection of air-tools, and who knows what else. I would very much appreciate input from those experienced in building a car audio shop.

My first series of questions is about ventilation. I plan to install a vent hood over the workbench area that I am using to work with fibreglass resins etc. The workbench will be at the back wall of the garage, furthest from the door. I plan to construct the “hood” out of drywall, with an opening about 4' wide by 2' deep, tapering at some point over some length to maybe 1'x1' or even circular 12” diameter, rising above the workstation before making a turn into the wall to vent outside. The channel would house an appropriate chemical filter, most likely where it starts at the apex of the hood. My workbench/fabricating station will be standard height (36"?). I plan to wear a chemical mask while working with chemicals but I wish to keep the air in the garage as fresh as is practical/necessary. I also realize that much fibreglass work will be performed in a car, and not on the bench under the hood. I imagine this is where the CFM capability of the fan is crucial in turning-over a decent volume of fresh air in the garage as a whole. The garage is 26’L by 19’W by 10’H, or +/-5000ft3.

is the 2' x 4' flared opening of the hood over the work bench sufficient? If not, what is practical? How low to the work area should the vent be? What about the taper and the size of the channel leading outside?

Should the fan blower motor be a sealed motor, or is this not necessary (I would like to be cautious in this area so I will most likely err on the side of caution with a sealed motor…).

What about the type of filter, and placement of the filter? What about the nature of the output on the outside ducting? any special configurations or conditions?

How often would I need to completely refresh the air in the garage? For instance, a 900 CFM fan is theoretically capable of bringing in 5000ft3 of fresh air every 5.5 minutes. I would leave the garage door open slightly at the bottom to allow air in. However, I am in Canada and plan to work in the winter. A strong fan might keep me a little too cold. Should I compare the fresh air turnover to the volume-warming capabilities of my heater? For instance, if my radiant heater can bring 5000ft3 of air from 30 degrees F to 70 F in 15 minutes, should I look for an exhaust fan that takes at least this much time to refresh the same area? or should the turn over be twice the heater’s capabilities (e.g. 30 minutes total turnover against 30 minutes total warming)?

Which brings up my next question – heating. Are the fumes of resin, catalyst, paint, spray-bondo, etc. safe around a ceiling-mounted radiant gas heater? What issues are there in this regard, and what setups do other winter-climate people have?

The last series of questions I have is about electrical service. What do other people have in voltage and amp service? I am working essentially on my own, and sometimes with the help of another person. The only things I can imagine running at the same time would be

1) lighting (fixtures as well as hand-held/plug-in)
2) fan mentioned above
3) an electrical space heater @ 1500-2000W (if I opt out of the radiant gas heater)
4) a modest air compressor (amperage/wattage unknown at this point, maybe you can suggest)
5) a heat gun at 1000-1500W
6) some other misc. hand tool such as a saw or drill, assuming there is someone else working in the shop with me.

What electrical configuration is needed to support this? I am not doing the construction but I would like be informed so I can discuss it with the contractor.


Thank you in advance!