02-19-2009, 01:10 PM
So yeah...I made a mistake when purchasing the type of fan for this project. I'm not afraid to admit I screwed up either. So I hope anyone who has been following this thread catches this note before they purchase their own fan and plows forward.
I was talking to a guy who works in HVAC. Installs much larger airflow systems for a living. We got talking about my little project and when I mentioned what type of fan I was using he was like, "So you are just going straight threw the wall right? Maybe 8 - 12" of ducting at most?" I'm standing there, " Um no,...more like in feet." He goes on to tell me that Axial type fans are good in free flow environments and that the CFM's decrease drastically when placed inside ductwork. He mentioned that if I was just going straight through the wall to the outside, I'd be golden. He said chances are I could go ahead and see how it works, however he highly doubted that the fan would be effective at venting any fumes outside of the house. Plus the back pressure in the duct work could cause the motor to burn out faster....
I did some checking on-line and there are a couple of other websites, that confirm this, should have bookmarked the links, however I was a little disheartened by this development.
So back to the drawing board. I been looking at squirrel cage type blowers. Two Dayton Blowers in particular have grabbed my attention in particular.
Dayton 1TDR3
http://www.drillspot.com/products/433894...PSC_Blower
or
Dayton 1TDR6
http://www.drillspot.com/products/433891...PSC_Blower
So there is a choice to deal with here. Either one will move the proper amount of air for the length of duct required. The 1TDR6 which I am leaning towards has a smaller outlet about 3", however if I run it into 4" duct, it will reduce the static pressure inside the duct work and allow better air movement.
I've also decided to do a design change as well and convert the current booth into a downdraft. Reason being is that either of these blowers if mounted on the back will require an extra 90 degree bend in the duct work adding 6 more feet to the overall run. (4" duct 90 degree bend = 6' straight duct). It will also add height which I do not have. Overall advice I've been given is to keep runs as direct and smooth as possible. The fewer the bends the better it will all work together.
The design change will also require me to cut a large opening in the bottom of the 20" by 20" bottom and install a 3" plenum underneath the booth. I've already figured out how I'm going to accomplish this. Another hurdle I'm trying to overcome here is that I cannot seem to find a dealer who sells these fans or a similar product in Canada! Even the local Acklands Grainger does not list it on their website. I've e-mailed them, just waiting for a reply. Shipping from the States on an item this "heavy" is going to cost me too.
Maybe I'm not looking in the right places... :?
I'm chalking this one up to experience but planning to move ahead and get it done right.
I was talking to a guy who works in HVAC. Installs much larger airflow systems for a living. We got talking about my little project and when I mentioned what type of fan I was using he was like, "So you are just going straight threw the wall right? Maybe 8 - 12" of ducting at most?" I'm standing there, " Um no,...more like in feet." He goes on to tell me that Axial type fans are good in free flow environments and that the CFM's decrease drastically when placed inside ductwork. He mentioned that if I was just going straight through the wall to the outside, I'd be golden. He said chances are I could go ahead and see how it works, however he highly doubted that the fan would be effective at venting any fumes outside of the house. Plus the back pressure in the duct work could cause the motor to burn out faster....
I did some checking on-line and there are a couple of other websites, that confirm this, should have bookmarked the links, however I was a little disheartened by this development.
So back to the drawing board. I been looking at squirrel cage type blowers. Two Dayton Blowers in particular have grabbed my attention in particular.
Dayton 1TDR3
http://www.drillspot.com/products/433894...PSC_Blower
or
Dayton 1TDR6
http://www.drillspot.com/products/433891...PSC_Blower
So there is a choice to deal with here. Either one will move the proper amount of air for the length of duct required. The 1TDR6 which I am leaning towards has a smaller outlet about 3", however if I run it into 4" duct, it will reduce the static pressure inside the duct work and allow better air movement.
I've also decided to do a design change as well and convert the current booth into a downdraft. Reason being is that either of these blowers if mounted on the back will require an extra 90 degree bend in the duct work adding 6 more feet to the overall run. (4" duct 90 degree bend = 6' straight duct). It will also add height which I do not have. Overall advice I've been given is to keep runs as direct and smooth as possible. The fewer the bends the better it will all work together.
The design change will also require me to cut a large opening in the bottom of the 20" by 20" bottom and install a 3" plenum underneath the booth. I've already figured out how I'm going to accomplish this. Another hurdle I'm trying to overcome here is that I cannot seem to find a dealer who sells these fans or a similar product in Canada! Even the local Acklands Grainger does not list it on their website. I've e-mailed them, just waiting for a reply. Shipping from the States on an item this "heavy" is going to cost me too.
Maybe I'm not looking in the right places... :?
I'm chalking this one up to experience but planning to move ahead and get it done right.