02-19-2009, 04:02 PM
No apology necessary Andrew. I appreciate all the help I can get.
Hi Wayne,
I have a few reasons for not moving it to the top. I have no clearance to put the fan on top, my layout bench work is right there. From what I have read, including the article posted, updraft booths are not recommended as you have to work against gravity and particulate not trapped by the filter can fall down on to the painted parts once the fan is shut off. Although like yours I have seen other homemade booths built as updrafts and if they work then great...however, we are back to space limitations up top. There are some some limitations based on the workable area that I can build this in.
Going down below seems the best alternative as there is nothing underneath the booth. Down draft booths have the added benefit of using gravity to assist in venting, plus in calculating the CFM's required you can use a fan that does not need to move as much air as a an up or even cross draft booth.
The only reason I used the Axial Fan in the first place was because, it had more then enough of a CFM rating for my use...at least I thought it had. Secondly, the article although helpful as well as possibly perhaps a tad misleading mentions the use of Axial Fans in commercially available booths. So I figured why not use one for mine too?
The HVAC guy is not really a friend...more of a workplace "acquaintance". I would ask him, except in my particular job, things like making nice with contractors can come back and bite you in the arse if you know what I mean. :| I don't know when I'll see him again either as his trade comes by once in a blue moon these days.
Hi Wayne,
I have a few reasons for not moving it to the top. I have no clearance to put the fan on top, my layout bench work is right there. From what I have read, including the article posted, updraft booths are not recommended as you have to work against gravity and particulate not trapped by the filter can fall down on to the painted parts once the fan is shut off. Although like yours I have seen other homemade booths built as updrafts and if they work then great...however, we are back to space limitations up top. There are some some limitations based on the workable area that I can build this in.
Going down below seems the best alternative as there is nothing underneath the booth. Down draft booths have the added benefit of using gravity to assist in venting, plus in calculating the CFM's required you can use a fan that does not need to move as much air as a an up or even cross draft booth.
The only reason I used the Axial Fan in the first place was because, it had more then enough of a CFM rating for my use...at least I thought it had. Secondly, the article although helpful as well as possibly perhaps a tad misleading mentions the use of Axial Fans in commercially available booths. So I figured why not use one for mine too?
The HVAC guy is not really a friend...more of a workplace "acquaintance". I would ask him, except in my particular job, things like making nice with contractors can come back and bite you in the arse if you know what I mean. :| I don't know when I'll see him again either as his trade comes by once in a blue moon these days.