I am building a fume hood at home, but I can't find a good/cheap motor. Ideally under $200 and chemically resistant, I am looking for something around
460-500 CFM. I'm copying Tom's lab fume hood. https://www.youtube.com/watch?v=1oEaRjqA5-c. Where should I look for this kind of motor.Abromination - 26-11-2020 at 01:59
These PTech centrifugal blowers are fairly affordable and work almost flawlessly. It's quiet and the motor is isolated from the air flow, although the
inside blades could do with a coating of something to prevent corrosion (it hasn't been a big issue with for me despite abuse). I wouldn't choose this
exact model, I would look through some of their inventory and find what's best for you. I use a 276-500 variable cfm variant with a 6 inch duct,
although I didn't see it when looking this time around. 276 cfm seems more than adequate for my hood size, although they do sell 500+ cfm blowers.
[Edited on 11-26-20 by Abromination]Fyndium - 26-11-2020 at 02:04
Might be unadvisable, but I use duct fans that cannabis growers use. I have 500 and 1000m3 models made out of polyethene, the high air flow keeps
concentration so low it causes little stress on corrosion or flammability. I don't leak LPG, hydrogen or other high concentration vapors there though,
primary reason is for odor control and then for corrosive stuff leaks like NO2, ammonia, non-flammable but harmful fumes etc.Belowzero - 26-11-2020 at 15:00
I am not intending to hijack this thread but it seems like a good opportunity to discuss.
Recently I obtained a very powerful fan and I wonder , if the flow rate is high enough does chemical resistance really matter that much?
If enough air is being moved around it would also dillute the corrosive molecules to such an extend that it is hard to imagine that the fan is
attacked at any noticeable rate..
I plan on coating the inlict with PVC or something similar to at least provide some form of protection although I doubt this is really required.
Any input?
Also would it be viable to coat fan blades without disrupting the balance of the motor or would inconsistency cause vibrations to an extend that it
would shorten the lifespan beyond acceptable limits? Triflic Acid - 27-11-2020 at 17:02
750 cfm is perfect and is probably more powerful then needed, although the motor is inside of the airflow pathway and will likely corrode overtime. It
also can pose a fire risk if it sparks while venting solvent vapours.macckone - 30-11-2020 at 02:00
Most blowers designed for hydroponics are brushless and have coated windings to reduce corrosion.
Of course they expect corrosion to be caused by organic acids and water vapor, not chemicals.Fyndium - 30-11-2020 at 06:18
This came up elsewhere but most if all duct fan motors are brushless nowadays so there is very little risk of sparks. The brushed motors are somewhat
old technology, still used apparently because they're cheaper.
I find EX proof stuff so prohibitively expensive that it would be total deal-breaker when buying something. It can cost 10 times the similar otc
product. For example ex proof flashlights, that still use ordinary incandescent bulbs and are very dim and close to useless other than in very dark
environments, costs 100€ a piece while a good quality 1000lm led light costs 5€. Ex proof inline fans could go from 600 to 2000€.
