this shows how to run fan,[pic one] the thermastat turns the fan on off for flower room,when off the heater keeps it warm until lights come back on. i use a welding rod with flux tapped off,pushed through the wall,shaped to fit through knob on heater ,adjust heat without opening door.you can see where rod comes through wall in pic 2,,also the 3in pipe lets a lot of air through,,now when lights go off i have a small fan from a small Elec: heater to move just a little air when lights are out in flower.this was a challange to fit to pipe,i used cardboard an duck tape,a timer to turn fan on after lights out.[pic3] showshow i get rid of the air,this vent has round bottom 8in pipe,goes under to ground,in ground all the way to woods,therefore no oder.be more later on how to water when you get this far..