Thread: Exhaust Fan

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I need a little help adding a speed control to my exhaust fan in the shop. It's a
shutter mounted exhaust fan.
1/3 H.P. 1725 rpm 115 volt
cont duty cycle split phase
air over fan motor fla 4.8 sf 1.0 sfa 4.8
I found this controller:
KB Electronics 8811014 Solid State Variable Speed AC Electric Motor Control, 8.0 Max amp, 115V, # K177-1008: Fireplace Fan Speed Controllers: Amazon.com: Industrial & Scientific
Will this do the job? want to be sure I pick the proper control.
Thanks, Rich

why are you slowing it down ?

went away before i finished. is this a fan mounted directly to the motor ?
an increase in intake area will help. i am rebuilding my booth doors to add another row of filters to cut down on turbulence in the booth.

shine, yes the fan is mounted directly to motor. There are many times when working in the shop I would like to run the fan slower
while sanding, or just to keep some air flow going with less air noise.
Rich

Originally Posted by RichB

shine, yes the fan is mounted directly to motor. There are many times when working in the shop I would like to run the fan slower
while sanding, or just to keep some air flow going with less air noise.
Rich

I'll have to do some digging to come up with specifics of my parts/pieces, but I installed a gable mount exhaust fan w/shutters in the barn to exhaust the painting area, and also thought that a speed control would be nice. I found that when I cut the speed back the fan motor got hot, to the point that it would trip out on the thermal overload and it would not re-start until it had cooled down.

Roger, mine also has shutters with a 90 degree exhaust hood on the outside wall. It has a
Dayton enclosed motor, not sealed though. I would probably never run it less than half speed.
Would the controller I linked be suitable?
Rich

i think it depends on the motor. some can not be adjusted like that. my fan is outside but still pretty loud.

Normally, split phase (motors with start and run windings), have start windings controlled centrifugally and drop out by means of a mechanically switch at about 75% of their rated RPM. This type of motor does not play well with electric speed controls. As the RPM is lowered it forces the start windings to re-engage and the motor quickly over heats.

If noise is an issue, you can connect fibre-flex ducting to the fan and distribute the intake to several areas thus reducing the noise and loftiness of the exhaust. The fibre-flex ducting in itself will lower the noise, but multiple inlets drops the noise to almost negligible. I have used this method with the fibre-flex to exhaust sound studios very successfully.

Here's the exhaust fan: (20")
[IMG][/IMG]
[IMG][/IMG]
Here is the intake in the ceiling at the other end of the garage. It has screen, filters, and pulls air from the eaves.
[IMG][/IMG]
It works pretty good for a one stall shop. It sounds as if I'm stuck with a single speed though.
Rich

You could take a look at places like Grainger dot com and see what a 2 speed motor costs? ( expensive I'd be willing to bet, but it'll help?)

That may be my only option, your right though probably pretty pricey. E-bay may be worth a look.
Rich

https://www.plumbersstock.com/mars-1...FZeEaQod94YEow

Get more speakers for the shop sterio!!!!!!!!

Actually-----most fans like that are mounted upper level and pull air up into upper eaves area to vent out ---------you have got the system reversed

If you put the fan upstairs you won't hear it.

On an whole house attic fan I installed 40 years ago, vibration kept me awake at night(fan mounted in the ceiling in hall way just outside the 3 bedroom doors) fixed it by using elrctric "B" hydraulic system mounts from Boeing 727

Originally Posted by jerry clayton

fixed it by using elrctric "B" hydraulic system mounts from Boeing 727

Iso-pads are cheaper and work as well.

we stole these