Why Servo Damper and Variable Speed Fan/Blower



New member
Hi All, I’m new to the forum and sorry in advance if I’m missing an established thread on this topic.

That said, if you have a variable speed fan/blower, what is the benefit of the servo controlled damper? Is one better than the other or are either only living up to their potential as a pair?

Also is the fan vs blower a settled debate or do even the persnickety temperature control gurus consider them equal?

Many Thanks,


They are complimentary to each other. The blower is used to generate air flow and the servo damper is there to restrict it.


TVWBB Diamond Member
The reason for the damper came about because on many grills the opening of the blower allowed enough convection air flow to pass through to overshoot the target temp, leaving the HM basically helpless to control your pit. Passive dampers of all sorts were devised to shut down that air flow but passive is not very reliable. A servo damper on the other hand closes off when the HM tells it to, effectively choking down the fire and lowering the pit temp. I also use my damper to control low and slow cooks with the fan off, running on convection air flow much like when you manually adjust the grills vents, which allows you to run the top vent open wider than you can with the blower.
As for blower vs fan, in general blowers create more static pressure, which translates in a greater ability to push air through restrictions. I think the fan designs work well enough for low volume flow like low and slow cooking on most pits, but a blower will push more air to achieve higher temps, recover temps faster and feed air to larger or more difficult to stoke grills.


New member
Very cool. Thanks for the clarification!

I’ll be ordering parts and getting my build going soon. Will post results when I have them.



I like the damper more than a fan/damper solution as well because the BGE's natural convection gets changed when a blower kicks in. What I see is that the fan blows the smoke out of the top of the BGE chimney when it kicks on. I've made some awesome BBQ that way nevertheless. What I like about a damper is that it forces the BGE to work the way it should whether it wants to or not. The way my damper works is that it never seals completely but rather allows just enough air to pass through to keep the fire going but restricts it just enough to keep it from running away and it smooths out the ups and downs. That's more important to me than seeing a flat line on 225.0F. I'll wander a degree or two in either direction but it happens over a long period of time.