Add speed control to old EF2 exhaust blower?

[bcarton]

I recently replaced the exhaust blower in my 1996 Enviro EF2. Even with the old blower, I could never get the draft setting to factory spec per magnehelic gauge. New blower is stronger, and with almost 15' insulated vertical rise, draft reading is even further outnof spec, especially on colder nights. I would like to add a speed control to the blower. Any recommenations? Could I use the same triac as used on the room blower? I can't close the damper any more. It's only open about .25" as it is.

Thanks, folks

 

[Fairwind]

The exhaust blower's function is critical. If the speed controller fails the blower stops and that can lead to disaster..If you MUST reduce combustion air, I would work on the existing damper before I rigged a motor speed control.