Duct fan

cybersurfer

Active Member
i seen a 4" 80 cfm and a 6" 250 cfm duct fan
i was wondering could i use a dimmer switch to control the fan speed?

what would you recommend 80 cfm or 250
i want to connect the duct fan to a diy carbon scrubber

i'm looking at a rubbermaid cabinet which is h 30" w 22" D 12" wish it had more depth

so what do you guys think?
 

Dirtfree

Well-Known Member
I am in the process of putting a dimmer switch on my intake and a attic fan thermostat on my exaust. Pretty simple stuff, but if you where to try and buy it from a hydro store they are about 75 dollars a peice. The dimmer is about 5 bucks and the attic therm is 12. I plan on making a carbon filter soon. DIY is the only way to go for me!
 

Dirtfree

Well-Known Member
that is a reall small space after you figure your light 24 inches away from your plants, if its hps, that only leaves you 6 inches of plant growth. You could use cfls and keep them alot closer to your tops. Might want to think of a different place to grow.
 

Dirty Harry

Well-Known Member
Be careful. Light dimmer switches are made forIndicasent lights and not for inductive motors. The lights dim when the dimmer adds resistance to the circuit, and producing some heat as a bi product.
If you have a high current motor instead of a normal light bulb, that dimmer can over heat.
I would get a multi speed can or buy a actual fan speed controller. The extra you spend just may save you from a fire and prevent another head line, "pot grow house burns to the gound..."
 

Dirtfree

Well-Known Member
Thanks dirty harry. I thought about that, dont need the fire dept. showing up. I got one thats for a fan motor, still only five bucks! Im surprised to see no one else using these attic thermos for their exaust. It does exactly what i need it for, it gets hot, it turns on then turns off, 12 bucks!
 

Dirty Harry

Well-Known Member
I think I know exactly what your talking about. A laundromat I do maintenance on has something like that. Behind the driers gets to hot it turns on the exhaust fans. When the back area cools down, it shuts the fans off.

If that is what you got, you got a good buy!
 

Dirtfree

Well-Known Member
you can get them at any home depot! They are for your attic fans, and you can get the replacement thermostat cheep! I mabe my entire system DIY. I think its part of the fun! With my new light i think i spent 600 dollars maybe.
 

cybersurfer

Active Member
that is a reall small space after you figure your light 24 inches away from your plants, if its hps, that only leaves you 6 inches of plant growth. You could use cfls and keep them alot closer to your tops. Might want to think of a different place to grow.
ya i'm using cfls all the way in a 4 bulb vanity fixture.
seen this guy on another forum do that in rubbermaid tubs {same height and he got amazing results.
 

cybersurfer

Active Member
Be careful. Light dimmer switches are made forIndicasent lights and not for inductive motors. The lights dim when the dimmer adds resistance to the circuit, and producing some heat as a bi product.
If you have a high current motor instead of a normal light bulb, that dimmer can over heat.
I would get a multi speed can or buy a actual fan speed controller. The extra you spend just may save you from a fire and prevent another head line, "pot grow house burns to the gound..."

thanks for the help
I did see some fan speed controllers i'll use that
 
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