Fan controller causes fan to over heat

So I just hung two new 12 Inch fans, one for exhaust and one for intake. Since the intake doesn't have as much resistance I put it on a speed controller. Just a cheap ideal air speed controller. But the fan overheated and wouldn't turn on for some time after being ran on the speed controller at 3/4 speed.

I don't know much about the fans, the hydro shop was back ordered on the fans I usually get but was able to get these for me. https://trimbuddies.com/products/95...MIj6-zlLi97QIVTvHACh1DpwI_EAQYASABEgLTWPD_BwE

I need negative pressure in the room, so I need to slow that fan down. I have thought about adding more resistance with some 90 degree elbows and longer duct but I'm not sure that will slow it down enough.

Do they make speed controllers that will work with those fans?

You want to use a variac or a trinary capacitive switch.
The cheapo speed controllers are triac based and kill motors.

7CardBud said:

You want to use a variac or a trinary capacitive switch.
The cheapo speed controllers are triac based and kill motors.

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Those ones you mentioned won't cause the fan to overheat or damage it somehow?

Some info...

@Renfro do you have any ideas I'd really like to fire up this room tomorrow, running out of space in veg. I'm thinking either a variac style controller, still not sure where to find one, or trying to make more resistance on the intake.

Well...I just looked quick and they don't make trinary switches that even come close to 5A. They are designed for ceiling fans and top out at about 2.5A.

Apalchen said:

Those ones you mentioned won't cause the fan to overheat or damage it somehow?

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Variacs don't distort the sinusoidal waveform and deliver clean power to your fan without damage.

You want to look for a variac that is 12A minimum to run those fans.

Bench Top 20 Amp Variac Variable Auto-Transformer with LCD Digital Display (circuitspecialists.com)