A little late for this season. I installed an easy combustion make-up air system for my Tarm. On Saturday I went to a surplus store and found a 6" linear actuator, 24vdc. My shop windows (2' x 4') are sliders, so I installed the actuator on one window and have a relay wired up to the flue temperature sensor so that when the flue is above the set point the actuator is "on" and opens the window, and when the temperature drops below the set point the actuator is "off" and closes the window. Really slick. The actuator also works fine on 12vdc.