Hey! I'm new here, but been growing for 35 years. All outdoor till last year when I set up a couple tents and some diy rdwc in my old band room.
The band room is an add on and isn't on the house ac. I use negative pressure to pull AC from the main house during the worst heat of Summer, but to avoid wild swings and be efficient during the other three seasons I've rigged up a way to use two temp controllers to bring cool outside air in from outside, but only when inside ambient temp is warm enough to want it AND the outside air is cool enough to help.
So pardon if this has been covered but here's what I did...
I installed a 6" vent booster mounted in a diy window flange pulling air in and ducted over to blow on my intake filters.
I connect the power of that booster fan to a heater controller then route that sensor outside and up under the eve in the shade. That sensor will measure outside ambient and call for power to the fan when the sensor reads below 68*f. This time of year our highs are right around that. (That changes drastically but the system is flexible)
First night I just ran that and in the morning the outside temp had dropped into 30s so room temp was 55*f. Whoops. So I went on to the next step.
I plugged that first controller into a cooling controller and route that sensor into my tent (I could just measure the room ambient but the tent is always a degree or two higher from the leds and gets the cool air I'm moving blown directly on the intake filter so it seemed to make sense to trigger off the tent temp) I set that at 70*f. When inside ambient rises to 70* it triggers power to the first controller, which then checks outside temp and if it's below 68, triggers the fan.
When it starts getting really hot July-Sept I vent both tents outside and flip that fan booster to exhaust when it's hot inside. The negative pressure pulls house air in and house air is nice.
Right now were still using the heater at night in the house so I have another 6" blower fan blowing warm air into the house when the grow room ambient is over 72. No point venting warm air outside while the heater is on.
The result of all that is that my grow room is exactly 68* every morning. When Summer is at it's peak that ambient temp will top out around 74* in the late afternoon.
I don't run any grow specific A/C and no active water chillers. I do passive cool the water otherwise the res temps would follow the ambient into the mid 70s.
The band room is an add on and isn't on the house ac. I use negative pressure to pull AC from the main house during the worst heat of Summer, but to avoid wild swings and be efficient during the other three seasons I've rigged up a way to use two temp controllers to bring cool outside air in from outside, but only when inside ambient temp is warm enough to want it AND the outside air is cool enough to help.
So pardon if this has been covered but here's what I did...
I installed a 6" vent booster mounted in a diy window flange pulling air in and ducted over to blow on my intake filters.
I connect the power of that booster fan to a heater controller then route that sensor outside and up under the eve in the shade. That sensor will measure outside ambient and call for power to the fan when the sensor reads below 68*f. This time of year our highs are right around that. (That changes drastically but the system is flexible)
First night I just ran that and in the morning the outside temp had dropped into 30s so room temp was 55*f. Whoops. So I went on to the next step.
I plugged that first controller into a cooling controller and route that sensor into my tent (I could just measure the room ambient but the tent is always a degree or two higher from the leds and gets the cool air I'm moving blown directly on the intake filter so it seemed to make sense to trigger off the tent temp) I set that at 70*f. When inside ambient rises to 70* it triggers power to the first controller, which then checks outside temp and if it's below 68, triggers the fan.
When it starts getting really hot July-Sept I vent both tents outside and flip that fan booster to exhaust when it's hot inside. The negative pressure pulls house air in and house air is nice.
Right now were still using the heater at night in the house so I have another 6" blower fan blowing warm air into the house when the grow room ambient is over 72. No point venting warm air outside while the heater is on.
The result of all that is that my grow room is exactly 68* every morning. When Summer is at it's peak that ambient temp will top out around 74* in the late afternoon.
I don't run any grow specific A/C and no active water chillers. I do passive cool the water otherwise the res temps would follow the ambient into the mid 70s.
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