CFM's lost

[hooterville75]

Does anyone know if their is a formula or equation a person can use to figure out the amount of CFM's a person will lose from the original amount of CFM's the fan will give off after hooking up the exhaust system to a spray booth ?

 

[Jelly]

Hi there,

Theoretically, from an (very VERY orthodox) engineering point of view, you should begin to design a ventilations system knowing, more or less:

• relative density (checked against air density: heavier or lighter) of the airborne subject that you want to remove (in this case you would remove an aerosol, wich is heavier than air), and
• volume of pollutant (per time unit) that it is going to generate the process
• where do you intend to take the pollutant from, and where do you want to finally put it…

Then, you:

• Will be able to select de appropriate geometry & dimensions of the pollutant exhaustion system, and
• The proper “fan” (power, exhausting capacity).

All that can be properly & finely calculated…

I studied that in detail a long time ago, but as I don´t use it in my job since 15+ years ago, now I´ve forgotten the essentials...

If you are very interested, and you live in the USA, you have a BEAUTIFULLY practical & simple book from ACGIH: “Industrial Ventilation: A Manual of Recommended Practice.”

Here you have some sample of it: http://www.cdc.gov/niosh/pdfs/74-177-w.pdf

I keep mine as a treasure of practical engineering.

IMHO the best & more practical that you could do is follow the direct advice of the veterans around … a lot of them (not my case) have built very fine hoods !

Cheers
RG

 

[Neo]

there a web site of a guy doing a spray booth DIY that has all the pipes calculation ect

ill try to find the link and post it later

 

[Neo]

GOT IT

http://www.briansmodelcars.com/tutorials/tutorial/23