EKO/Tarm 60 fan question

[Sizzler]

Has anyone disabled a fan to extend burn times/save energy on the EKO or Tarm 60? (not sure if Tarm has dual fans) I've been experimenting with burning one nozzle blocked off with a piece of plate steel during warmer weather and have had good results as far as extended burn times and low stack temps. I messed around with the fan openings tonight while everything was up to temp and it appears that two fans are not really necessary to accomplish good gasification through one nozzle or perhaps even both nozzles. I'm thinking of wiring in a switch to cut power to one fan and then just open the slider a bit more on the working fan as needed. When the weather turns really cold I can just switch back to dual power.

 

[jebatty]

Assuming the Tarm 60 fan setup is the same as the Tarm 40, I doubt this boiler would work without the draft fan, unless a person had unusually high chimney draft to create the downdraft needed for gasification.

That said, I installed a fan motor speed control on my Tarm to give me some flexibility in regulating the draft. With outside temperature variability, dryness of wood variability, type of wood variability, etc., I found that the speed control better enables me to keep stack temp in the 400 range, regardless of variables. I think this translates to better overall boiler efficiency, rather than letting stack temp stay much higher or go too low. Still not perfect, and an automatic modulating draft fan speed control would be better. Stack temp is not always the best measure of boiler efficiency, and a modulated system would need to be more complex (O2 and CO control, for example) to perform its function.