I did redesign the room. I raised the filter to the ceiling. moved the exhaust fan to the attic, the end of the run. I lost some circulation because when the fan has to suck the system, the flex duct accordians and volume is lost even with hard duct at the elbows. a little less air flow makes a difference of a degree or two and that matters. to me it does. I also diverted a duct from my swamp cooler into the grow room. the air enters thru a damper near the ceiling caddycorner from the exhaust filter. I just finished the dry run and the results are. in real time (2:00pm) the outside temp in the shade is 106. grow room temp is 90 degrees with everything running. after sundown the temp in the grow room drops about 15-17 degrees. if I turn the light off for 6 hours a day how much slower will it grow?