We're finally in the process of getting an exhaust system and electricity added to my new studio. I've been reading and reading and all the math involved is giving me a headache (literally).
What I'm understanding is that the only measurement that matters in deciding on what size fan to get is the opening of the hood...which we haven't had fabricated yet. Is this true?
The hvac man was here a couple days ago to look at the studio, which is 10x12 and give an estimate. He had no clue what we needed and said we have to figure out our exhaust requirements and then tell him what we need installed. He did mention installing a 800cfm high velocity fan with a controller that allows me to dial it up or down.
I like the design of Mary's studio in this thread
http://www.lampworketc.com/forums/sh...d.php?t=265333
and that's what we're modeling mine after. I plan on having makeup air coming in from the side and up under that back of my bench. But now I'm worried that if I have air coming right up under my hood, that it won't pull enough contaminants away from my face area. I do have two small windows behind me on either side of the door so one or both could be cracked open. I just want to be able to work as long as possible during the cold months.
1. We need to decide on a hood size (30x30 is what we were thinking) but now I think I need an actual box to capture and funnel fumes. Originally I didn't want a fume hood because I was worried about it getting in my way, reaching to the sides, etc. Safety has to come first over convenience.
2. Then after we decide on the size for the extraction hood/box I have to multiply (say 2x3 box opening for example) by 125cfm? And that's it?
3. What about makeup air coming in from outside through 8 or 6 inch duct and under my bench and hood? Will I still need to have the back window open?
4. The exhaust is going straight up through the roof. I originally wanted the fan outside to help keep it as quiet as possible but the hvac man thought that was not the best idea (how to keep out bugs, critters, weather, etc.) He also mentioned having a cap on the end of the exhaust duct, like we have on our home roof where the water heater vents. I forgot what he called it (B pipe or something).
I appreciate any help. Thanks!
~Tracy