How do you think this would work for exhaust venting?

[bad_idea]

After spray painting in the garage today with the door closed (to keep temps up) I now have to wipe everything down because it is all cover in over spray dust. I really need to install some sort of exhaust ventilation.

I am thinking the air intake for the central heat and air in the house would work well. Thinking I could use the grill, filter housing, and blower motor and then plumb it to the outside. Not saying tie into my existing, but to install a separate one in the garage ceiling controlled by a wall switch. Should be able to scour Craigslist for the parts I need. I have no HVAC experience so I am not sure how feasible this is.

 

[stonewellmark]

Check Cl for oven range hoods with outside exhaust. But what you have in mind should work well too.

 

[79firebird]

i find an old fernace fan works good

 

[e-tek]

Anything that exhasuts it outside will work - to a degree. If you are spraying with a gun (lots of overspray), then you need to get something strong enugh to change the air every minute or two. A quick volume calc will tell you which size fan will do it.

Also, make-up air has a lot to do with how well and fast OS/dust gets evac'd. I have a 1/3HP wall fan - VERY strong. If I crack the the roll-up doors a few inches, it'll clear the shop in minutes, but if I just open a window, the air gets sucked from the window to the fan, while OS hangs around in the other areas.

I built a small-parts paint booth with a fume hood that is perfect for spray-cans, but if I'm using a gun to do larger stuff, I hang pastic sheeting from aircraft cables to close off 1/2 the shop. Wiht the wall fan it's a side-draft booth.

 

[MustangRick]

I have an old funace fan mounted into a plywood box that I use for things like this. The box stands about 5' tall and ***** the air in along the bottom foot or so and all the air is forced up and out the front. Works really good for cooling down in the summer, and flip it over and it works great to ventilate out from under the garage door.

 

[bad_idea]

I do more welding and grinding than painting. The occasional wood working (nothing fancy). I don't own a spray gun either. The garage is a 14x20x9 attached garage.

 

[BWS]

Its all about the make-up air.Figure out how much of it you have to "spend".....then calc how fast you need to "spend" it to clear your booth to satisfy health/air quality.Spend wisely.....

The motor/lights/electrics come into play here.......you're literally playing with fire.Its not impossible to create a safe,well working vent system.But make sure you're making an apples to apples comparo WRT "rollin your own" vs buying a used commercial say,1/2 open version.The latter will have a pretty good return on your investment $$.....buying a "lable'd" unit.....when/if you need to sell.Any monies put into a homeboy special "may" not be worth much.Sometimes guys think they're saving $$ when rollin their own....thats usually because they're not adding up EVERYTHING involved in build.Just becasue you're spreading the $$ out over a period of time......don't mean its cheaper.

Whichever way you go(used commercial or homeboy).....you need to run the calcs for consumables....mainly filters.Floor space requirement is a story in itself.....I like the 1/2 open style booth because of this.But theres limits to them in the size of project.Will leave the litigation and EPA side of it up to end user to decide for themselves.BW

 

[bad_idea]

that is alot of information above my knowledge level. I just want to **** welding smoke out of the garage. The occasional spray paint fumes. I was thinking a furnace filter across the air intake for the exhaust fan to keep it from sucking dust and dirt onto the roof.

 

[Copytech]

Old furnace parts can be had for cheap. Just call a small HVAC company and ask for used parts. You might even get them to install it for you at a reasonable cost.
Larger firms will usually try to sell new parts, or hang up on you.

 

[jimindm]

Some here have mentioned venting to the outside. Keep in mind the air you are venting has to enter from somewhere else. The larger the output the more air needed to come back in. Pick a fan that is sized right.

I have an attic vent built into the wall, louvers and all. Works well. City made me put it in when they permitted me to have a repair shop in my garage. They wanted a flow rate of 2 1/2 times the floor space. In the summer its just fan that blows outside. As it gets colder out, it hardly ever runs. I like a warm shop, and a natural gas reznor works well. If you turn the fan on in the winter, you must crack a door, otherwise the chimney for the reznor is the incoming vent. If the furnace is on, that is not good. You open a door and it cools off rather quickly.

A hanging plastic, make shift paint room works for me. I have seen the table top paint boothes built by people on here. I could get away with one of those most of the time.

So however you are keeping the temps up, and the size of your shop, may help you make your decision.

 

[NUTTSGT]

When I painted my tool box, I stuck a box fan in the window with a furnace filter on the intake side. Then I propped open an attic access hole. It took care of most of the over spray.

 

[mad57]

The op states (to keep temps up) i would use 2 cheap box fans and some house central air filters taped together and sides and top from card board and direct over spray into the filters that way you can recycle the heated air and not have over spray. no venting outside at all. youll still have the smell but little to no over spray everywhere.

 

[AMCguy]

I think the best way to minimize heat loss, is to use as little of the garage space as necessary to handle the painting task.

How about a large cardboard box sitting on a table (a mini paint booth). All you need is a small ducted fan on the back side of it leading to an open but blocked off window. The fan only needs to run while you are painting to get rid of the overspray. You can turn it off immediately afterwards. A lot of the fumes you usually get are from the overspray. If you get rid of them right away you only have to deal with the fumes from the drying part.

 

[bad_idea]

I am thinking a vent fan through the wall with louvers may be my best option. Then build a basic frame across it to hold a furnace filter. The majority of stuff I do in the garage is welding and grinding. So going to the trouble to build a paint booth for the odd ball thing I may spray paint would be excessive I think. Then crack the roll up door for air intake. Unless someone has a better air intake method. I am also curious to see what others have for exhaust fans with louvers.

 

[61falcon]

should the op consider a fan that wont have any arcing from the electric motor that could ignite any fumes from painting?

 

[edl]

I am also curious to see what others have for exhaust fans with louvers.

http://standardequipmentco.com/blowers/31--(HA-2)-a.htm

dayton makes something similar (sold at Graingers)