Fumes ventilation

[flexysteve]

Hi everyone,
I'm buying a home and want to find a good way to vent the garage. I do alot of painting, fiberglass and carbon fiber work and the fumes are terrible. I want to setup a good ventilation system. The garage has no windows and I don't really want to add any but it does have a unfinished attic with 2 non powered vents. I don't really want to cut a hole in the side of the new house to add fans either. Is there a good powered roof fan that could draw air through a partially open garage door. Or should I design a booth of sorts and run a vent tube up to the roof?

Thanks in advance

 

[Uncle Buck]

Since this is for your home; I will not go into my windy ditribe regarding the safety aspect of explosion proof rated wiring components when ventilating fumes that could cause a sploshion. Judging from your attachment, It would seem to me the only logical direction to install any ductwork would be up. Obviously regardless of whether you are pushing or pulling air from the top you will need to be able to move enough air to get at least several exchanges of air an hour in the garage. I am no engineer, nor am I an Industial Hygienist (in my job this would usually be more of a Hygienist type issue) I am simply going to make a guess that if you cracked the overhead door a bit for intake, and exhausted through the roof, you would be more inclined to pull in a greater volume of contaminants low to the ground that might end up in your finish (painting?) This would seem to be the easiest way to ventilate the area. If you have enough distance between the intake and exhaust sides to realize the full benefit each one will provide to sufficiently ventilate the garage, I think you would get cleaner air both pulling and pushing from the top. This way would definitely involve more material expense and time to install, however, I do think it would be your best option. The critical information you should pose to the engineer types that frequent this board are, the room dimensions, and the distance from the ceiling in the garage, to the roof. Also, if you are determined to use a particular size of stove pipe you might share that as well,(size diameter matters) additionally purposed motor/fan specs. Armed with that information a good engineer should be able to tell you how how much air an hour you will move in and out of that space. Your MSD information for the products you are using would surely factor into this greatly due to issues such as vapor density and the rest of the product specs. If I were going to do this without using explosion proof components (not recommended) I would try and locate the fans as remotely to the spraying/application area as possible (at the roof) to hopefully introduce air with a lower concentration of the chemical to the fan motor, more so on the exhaust side than the intake side, at least in my humble opinion. I hope that helps and I did not steer you wrong in any way.

 

[kbs2244]

What he is saying is that you need a lot of low speed air. That means big holes and slow fans. Opening the door 6 inches is the cheap way to get it in, but you run the risk of dust getting blown around.
You are playing with some nasty stuff for an attached garage.
I would plan on a 30 x 30 inlet vent placed low and with a filter and close to the house. Then the same sized powered outlet vent at the other end of the room going up through the roof to pull everything away form the house.
You should look into where the wind will blow your exhaust also. A swing set downwind would not be a good idea.

 

[Uncle Buck]

There is no reason you should not be able to accomplish your goal without using anything larger than say 10" stovepipe. I do not understand the slow moving fan concept referrenced above, usually when powered vents are used in paint booths, or in industry, they are higher rpm fans?

 

[bmwpower]

Subscribed....I'd like to know, too.

 

[Uncle Buck]

Subscribed....I'd like to know, too.

 

[bmwpower]

Subscribed, as in subscribed to this thread for future info.

 

[Uncle Buck]

Gotcha, It's the Old Timers Disease, it gets me down sometimes!

 

[DekeT]

Revived to ellicit more discussion. I would like to exhaust some of the dusty air and welding fumes in my shop.