Variable speed house fan motor

[Toolfreaky]

I have a house fan with GE 5kcp39hg motor that has a off/hi/lo. I'd like to make it a variable speed house fan. What are my options? Has an adjustable belt system.

 

[dogdog]

If you decided to kept that same motor, your available options electrically is Off/high/low.

Mechanically? Not sure what you can fit

 

[Shiftless]

The motor name plate says 1100 RPM. Are you sure it’s got high and low speed? How does that work?

My whole house fan has a 2 speed motor. I installed it myself and ran wires down to a timer and a SPDT rocker switch that selects high or low. Sometimes low is enough. And sometimes we need high for a while even though that raises the fan noise.

 

[Shiftless]

Are you sure you need something in between high and low? Why…may I ask???

 

[dogdog]

The motor name plate says 1100 RPM. Are you sure it’s got high and low speed? How does that work?

My whole house fan has a 2 speed motor. I installed it myself and ran wires down to a timer and a SPDT rocker switch that selects high or low. Sometimes low is enough. And sometimes we need high for a while even though that raises the fan noise.

the fan motor have that brown brown cap, then white black red probably for speed.

 

[whateg01]

If I "needed" to convert my attic fan to variable speed, I would get a 3ph motor and a vfd.

 

[American Locomotive]

You could try a variable speed ceiling fan speed controller, it should probably work okay enough.

The "best" way would be to get a small 3 phase motor and a VFD, but that's an expensive solution.

 

[Toolfreaky]

Looking for a lower speed because it's next to the living room and bedroom so it's loud even at low. It would be nice to have slight exhaust.

I also have s off/high/low switch and then a timer I turn, so that is how the speed is adjusted

 

[whateg01]

Change the belt and pulleys

 

[Toolfreaky]

Change the belt and pulleys

Hadn't thought about that. Good idea!

 

[larry_g]

Change the belt and pulleys

X2 on this....Just go to a larger driven pulley. Also look at how things are mounted, you may want some vibration damping mounts.

 

[Shiftless]

X2 on this....Just go to a larger driven pulley. Also look at how things are mounted, you may want some vibration damping mounts.

Beat me to it for that suggestion.

When I installed mine, I let the whole assembly float on sponge rubber pads to minimize vibration transmission to the ceiling joists.

If the current “high“ speed setting moves plenty of air you could install a bigger pulley on the fan blades or a smaller pulley on the motor and that will give you a lower speed and probably less noise. But of course, that will reduce the CFM of your fan.

BTW, do you have plenty of square inches of exhaust area in your attic? That affects the CFM.
I had to add an extra huge gable vent when I put mine in. I move 8000 CFM with mine.

 

[fitter30]

What ever motor you pick it has to made operate in the vertically and shaft up or down. Also has to be ball bearing. How do u want to control speed manually or ?.
Vfd can't be mounted in a attic with all the heat. 4 speed motor?