Home made roofvent

Son of Norway wrote:
Use a PWM to control fan speed.

Thanks for the info

Use a PWM to control fan speed.

The fan is 12 volt 80 watt ,,, 1750 cfm .
I believe the fantastic fans are about 1000 cfm
I need to figure out a speed controller to slow it down .
Question ,, if I wire in a resister to slow the fan down will that cause it to waste power because of the voltage drop accross the resister or will it save power ,
I was thinking that when the resister was used it would have a voltage drop and get real hot and disipate power (losing heat power) that otherwise would have been running the fan full throttle and using all the energy.

Still editing

Clever. Tell us more.