ventilation and air conditioning

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Trojan46312

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What's up guys? Quick question...please help. The grow room is about 700 cubic feet with a 440 cfm exhaust fan. The intake is passive. To cool the room, there is a portable air conditioning unit when on high setting blows 456 cfm. Medium blows 396cfm and low blows 336cfm.. Will the exhaust fan suck out all the air before the air conditioner cools the room? How should I set the two for them to work together properly?
 
Trojan46312 said:
What's up guys? Quick question...please help. The grow room is about 700 cubic feet with a 440 cfm exhaust fan. The intake is passive. To cool the room, there is a portable air conditioning unit when on high setting blows 456 cfm. Medium blows 396cfm and low blows 336cfm.. Will the exhaust fan suck out all the air before the air conditioner cools the room? How should I set the two for them to work together properly?

The 2 just dont go together. No way around it. The AC will just keep spinning the electric meter and not really doing much. It might cool it, but at what cost?
 
So, if you sealed the room to use the ac and used the blower to cool the light drawing outside air and exhausting to the outside how would you make up for the lack of air exchange?
 
The exhaust from the air cooled reflectors is blown out the chimney. The intake is passive drawing air in from the basement. The air conditioner pulls it's fresh air in from outside. It's a dual hosed air conditioner. I forgot to mention the exhaust from the air conditioner is connected to the same exhaust as the reflectors with a y connector.
 
Can you cool your light with air from another space, if you can you wont be pumping ac air out the exhaust, you can run the ac with passive intake still.
 
Dman1234...the exhaust is hooked up to a carbon filter as well. So it's cooling the lights as well as cleaning the air. Maybe I need to get another fan huh?
 
This is just my personal opinion of how to make this work if you are in that much need for temp control.

I would separate the air conditioner from the vented hood and the passive intake. Then I would leave the intake completely passive. Then take the filter and put it on the open end of the light with the exaust from the light goint to the exaust fan going out.

Then I would take the intake hose for the AC and route it up to the top of the space, and the cooled out going air to the floor.

The you would use 2 timers, one for the blower and one for the AC(turn the AC to maximum thermostat setting with the blower on low). The timers would be set so that the blower and AC run at opposite times of each other. The blower turns off and the AC turns on and runs for 15min then cuts off for 30min, while the blower comes on for 30min and cuts off when the AC cuts on, cuts on for 15min, off for 30min, and the cycle repeats until night time when the lights turn off you can have the blower continue to run without the AC turning on.

This might take a little adjusting of the timing cycles to get it to work without wasting much energy and still keep the room at a livable temp during the hottest months.
 
I think we need to know about your lighting. A 700 cubic foot room is quite large--how much lighting do you have? I simply do not see a 435 cfm portable A/C and a 440 cfm exhaust fan being able to even begin to cool a space that large if it is properly lit.

It also can be hard on an A/C and fans to have them cycling on and off dozens of times a day.
 

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