Hey, just revamped my grow room and have a question about A/C. I grow in WA state and am a legal medical marijuana patient (cancer survivor here, 
).
I am currently running 4000 watts (3 1000 W HPS + 1 1000 W MH) in an airtight and insulated (R-19) room. The room dimensions are (approx.) 6' (W) x 13' (L) x 7' (H).
I am running CO2 out of a 20 lb. tank. The walls are white and the floor is reflective, covered in space blankets.
My problem is this:
I have installed a 24,000 Btu mini-split air-conditioner. The HVAC installer, when he saw the room, said right away that the unit was way too big and that I would guarantee have problems with the unit in the future. He admitted that he did not know anything about growing, or the lights used and the heat they produce. Still, the lights are only on for 12 hours a day. His concern is legitimate for the 12 hours they are off.
Now, I went with a 24,000 Btu mini-split for efficiency, and based on the approximate calculation of 3.414 Btu's per 1 watt of heat. And I gave myself a bit extra because I plan on adding to the room two more 400 W HPS lights in the near future.
So, to reiterate, the A/C unit is WAY too big for the space I am cooling WHEN THE LIGHTS ARE OFF. When the lights are on I am not having any problems. But in the off-hours, the A/C unit is turning on, then turning off, then turning on, then turning off, etc. etc. etc. This is NOT GOOD for the unit. I have considered running it on a timer--the mini-split has a built-in timer that would allow me to flip it on say, ten minutes before lights on, and power it off just after dark; but the problem with that is that the temperatures will run high during the day (especially now in the summer). So, I am wondering if anyone has any suggestions--also (please, say it isn't so!!!) if, like the HVAC installer said, I overshot with a 24,000 Btu unit. (He recommended a 9,000 Btu unit, which to me seemed laughable given the amount of heat the lights produce.)
Anyway, much thanks for any answers in advance. Hope to find a solution. Now that the remodel is done, I can't wait to get back to work.
).I am currently running 4000 watts (3 1000 W HPS + 1 1000 W MH) in an airtight and insulated (R-19) room. The room dimensions are (approx.) 6' (W) x 13' (L) x 7' (H).
I am running CO2 out of a 20 lb. tank. The walls are white and the floor is reflective, covered in space blankets.
My problem is this:
I have installed a 24,000 Btu mini-split air-conditioner. The HVAC installer, when he saw the room, said right away that the unit was way too big and that I would guarantee have problems with the unit in the future. He admitted that he did not know anything about growing, or the lights used and the heat they produce. Still, the lights are only on for 12 hours a day. His concern is legitimate for the 12 hours they are off.
Now, I went with a 24,000 Btu mini-split for efficiency, and based on the approximate calculation of 3.414 Btu's per 1 watt of heat. And I gave myself a bit extra because I plan on adding to the room two more 400 W HPS lights in the near future.
So, to reiterate, the A/C unit is WAY too big for the space I am cooling WHEN THE LIGHTS ARE OFF. When the lights are on I am not having any problems. But in the off-hours, the A/C unit is turning on, then turning off, then turning on, then turning off, etc. etc. etc. This is NOT GOOD for the unit. I have considered running it on a timer--the mini-split has a built-in timer that would allow me to flip it on say, ten minutes before lights on, and power it off just after dark; but the problem with that is that the temperatures will run high during the day (especially now in the summer). So, I am wondering if anyone has any suggestions--also (please, say it isn't so!!!) if, like the HVAC installer said, I overshot with a 24,000 Btu unit. (He recommended a 9,000 Btu unit, which to me seemed laughable given the amount of heat the lights produce.)
Anyway, much thanks for any answers in advance. Hope to find a solution. Now that the remodel is done, I can't wait to get back to work.
AND MAKE SURE YOU HAVE A GOOD CONDENSATE PUMP, or its piped to a drain directly. those bastards run a very low temp differential and pull moisture out of the air like crazy. compressors these days are built very well, these units go through hell typically in computer server rooms and what not. dont be overly concerned on the starting and stopping. they usually also have an anti short cycle delay, again, depending on make. fujitsu, samsung, lg are good quality brands.