I have a monster kitchen hood

I have a monster kitchen hood that can do 1100 cfm (and its needed if I'm grilling ribs!). Although the hvac guy put a make up air system into the ducting the hood works best if a window is open somewhere.

However, I'd think that for 250 cfm the problem would be nowhere near as significant (compared to 1100 cfm).

If you have rainy winter weather (like Oregon) a more significant problem will be humidity.

Cheers,

Charlie

Thanks for the feedback.. I

Thanks for the feedback..

I have two dehumidifiers going in the basement. One in winter. I am blessed (and cursed) with sandy soil. Between that and hunidifiers at both ends, my basement stays quite dry. Also mandated by my wife's extensive collection of old children's books.

Chris

Spray booth

Does anyone get a buildup of spray on the siding where the vent pipe goes through the wall?  I live in a freestaning condo and the 'powers that be' would not look favorably on my defacing their siding!!

Thanks.  Dick

I can't comment from direct experience, but..

I can't comment from direct experience, so take with a grain of salt, but from what I have read the filter should catch the overspray and it should just be fumes blowing out. I could, of course, be dead wrong. I hope not.. I will be venting into my wife's flower garden. She would prefer not to have weathered lillys..

Chris

Testors Spray Booth

 I just had my kitchen remodeling contractors install a spray booth in my basement with ducting to the outside. Since they were tearing up the basement ceiling to run some new wires, this was a good time to do the installation. They had to drill the opening through my concrete foundation wall because of a lateral pipe prevented them from reaching the stud wall. They did a nice job installing  it. 

I used a commercial Testors spray booth.  It is a downdraft type. It has a three stage filter. The included blower does 185 CFM It runs through about five feet of 4 inch ducting with two bends. The exterior has a typical dryer duct cover with a bird shield and movable flaps. 

Before exhausting to the exterior, I only used it to spray acrylics in the booth. Now I spray primer and dullcote in my shop. It is very convenient.  It seems to work pretty well. The draft is not very noticeable in hood, but outside you can definitely see the flaps open and feel the exhaust. I have not noticed any paint build up outside yet, but I haven't used it very much.

I sometimes open one of the small windows in my basement when I'm spraying. That seems to help with the venting. Since  my work shop is a dead end 5 x 15 closest with no windows, I run a floor fan to improve ventilation, especially when I am using model glue. I have tried also running the spray booth blower when building models at the workbench. It seems to help. Good ventilation is necessary when dealing with solvent glues.

How big of a downdraft platform?

Thanks for the info.. if you get a chance.. could you tell me how big of a downdraft platform was associated with the 185 CFM blower? I will be running through the same length of ducting. Two bends and about 5 feet up to a basement window. Rigid ducting.

The pro of a downdraft, from my reading, is you only need about 50cfm/sqft although I did not find OSHA stuff on that.. just what the word on the street is. The con I see is that you would interfere with the drafting if you put a big lazy susan in the booth over the vent.

Chris

Won't 50CFM downdraft simply

Won't 50CFM downdraft simply pull paint over spray down over the painted surface and cause rough texture.  My logic would say backdrawf would pull any paint fume away from the surface.  50CFM sounds like a slow breeze to me.  Would'nt a higher CFM rate  be better in this case ?.   I'm also looking into a paint booth for my modeling.

Marc

The car modelers love them

I don't know.. but the car modeling folks that are seriously uptight about a perfect finish seem to prefer the downdraft. Most of what I have read about spray booth construction came from model car forums. Not my interest, but I will learn from anyone that has something I can use to teach me!

Chris

+

You are further a head, I should have read the thread from the top.  Much of your info I also found here.

http://modelpaint.tripod.com/booth2.htm

Marc

Great link!

Thats a great link.. thats where I got a lot of my info. I verified some of the stuff elsewhere.

I am looking at a slightly different shape for the booth

Regards,

Chris

btw- found that testor's spray booth (http://www.testors.com/catalog_item.asp?itemNbr=6). Will take a look at the assembly instructions. Looks like it has almost 100 CFM (15x20 surface) before ducting, but probably closer to 60 after ductwork, off the cuff. Sounds about right for a downdraft although it seems very expensive, at least the msrp.

Chris

Finalized specs, ordered parts

I decided on building a backdraft booth around two square feet. Although I am slightly exceeding that,  I settled on 16x20. Thats an easy to find furnace filter size and is big enough to stick a piece of foam held in my hand with a few trees stuck in. I ordered the Dayton 1TDR3 blower (more to the point, won one on ebay..). Its 273 CFM but the static pressure in the vent out the window will greatly reduce that. I am ok with that though.. it is comparable to similar units made by Paasche and Badger. If it becomes a problem I will get the next model up at 495cfm.. but I like that the 1TDR3 matches up to the 4" piping that will fit in my small basement window well..

I have purchased some stuff I need to build it including the filter, a 4" duct starter, and some plexiglass. I already own the laminate particle board I plan to use for the base and sides. I still need to spec and aquire the electricals. I would like the vent and light to be on seperate power switches, and to have an outlet built into the same box as the switch.

I also hope to make the front half of the box's lid hinged so I can more easily spray trees when I am holding them in there. Probably need to wear a mask in that case.

I will post some pics on my Blog (here on the MRH site) when I am done, as well as some feedback on whether it is sufficient. I am somewhat under OSHA requirements, but then I am not spraying the really nasty paints. Primarily acrylic. If I do a solvent primer I will wear my mask.

Down the line I will play with making a downdraft booth.

Chris

I have a Dayton 4C447 coming

I have a Dayton 4C447 coming my way from Ebay.  We can compare notes.  The TDR3 was the replacement for the 4C447. Mine comes with a 4" round attachement  installed.   Been waiting long enough for a paint booth.

Marc