# Fume hood blower



## Williamjf77 (Dec 2, 2018)

I found this fan at surplus center in USA, ordered one to make my fume hood, 1000 cfm for 12.99. I’ll have to build it into the hood because of the way it exhausts but It seems like it should be good. It’s like a squirrel cage without the shroud. 

Anyone use anything like this before?

https://catalog.pelonistechnologies.com/Asset/FH280.pdfView attachment FH280.pdf
:roll:


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## snoman701 (Dec 2, 2018)

I think I would have bought one with the shroud. 

Just my experience. I've always spent too much time planning projects and not enough doing it.


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## Williamjf77 (Dec 3, 2018)

Haha, I thought I was the only one with all the “projects “

I couldn’t resist the price.

I’m debating using the fan with no shroud at the end of a duct with a little rain cover. That style could be on top exhausting in open air with the ducting going straight down through the roof in to the hood.


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## snoman701 (Dec 3, 2018)

It doesn't work like that I don't think.

Most radial fans create low pressure in the center of the impeller and high pressure on the outside. You'll have to shroud it in some way so it can build the pressure.

I've had one of these going for almost a solid year. I think I modified standard HVAC parts to fit inside the flange and it pushes air through a 6" piece of pvc.

If I could do it again, I would have just gotten a proper acid blower for the hood, spend the time and money the first time.

https://www.harborfreight.com/8-inch-portable-ventilator-97762.html

on edit added link


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## Dr.xyz (Dec 3, 2018)

Roof mounting is a good idea, inlet side just has to be reasonably tight fit with the duct.

Maybe two square metal plates connected together with threaded bars at corners? Bottom plate with duct size hole and fan mounted to top plate upside down. Threaded bars make it easy to adjust impeller clearance.

Then some mesh on the outside to stop debris and animals.


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## Williamjf77 (Dec 4, 2018)

From the info I have gathered it seems the backwards curved impeller fans can operate in a housing or without,the fan guys call it a “plenum” when it isn’t in a housing or shroud. Which I envision on top of my hood enclosed in a box with the outlet wherever I need. 

I’ll probably just mock something up and test before committing to a permanent solution, which I think I’d use fiberglass or frp sheets in some way. I don’t want the thing to weigh a ton. 

Fiberglass is easy, and I can weld (meaning grind) to whip something up.


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## Williamjf77 (Dec 4, 2018)

Honestly exhausting the fumes doesn’t seem too difficult it is what you do to clean the air that makes all the difference. 

I have plenty of glassware from previous chemistry experiments so I think I will just do all reactions in sealed vessels with a reflux column and a gas adapter to a suck back trap scrubber and just directly vent what the scrubber doesn’t get. I have neighbors reasonably close to garage like 50 feet. but I think their wood stove is worse for their health than what I’d be releasing.

I don’t do anything large scale I’d just rather use nitric than AP for the speed of it. It’s winter in New England so AP is extra slow unless I keep it heated.


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