I am shopping for a mini split unit for a grow room which is relatively small. The unit will cool a lung room that houses multiple tents and equipment.
The lung room is 11x12 with 8’ ceilings, 132 square feet, 1056 cubic feet.
I’ve decided to go with Mitsubishi and I need around 12k btu. I have two options and this is where I could use some help. I will be using a horizontal ducted mini split installed in an attic space using 10-12" ducting to the return and supply.
The models in question are SEZ-KD12NA4 and PEAD-A12AA8
Both are 12k btu, the main difference is cfm, gallon/hour of dehumidification and static pressure
SEZ
airflow rate cooling cfm - dry - 247–317–388
airflow rate cooling cfm - wet - 222–285–349
external static pressure 0.02–0.06–0.14–0.2
Dehumidification Rate: 0.24 gal/hr - 1.92 pint/hr or 46 pints/day
PEAD
airflow rate cooling cfm - dry - 353–424–494
airflow rate cooling cfm - wet - 318–382–445
external static pressure 0.14–0.2–0.28–0.4–0.6
Dehumidification Rate: 0.14 gal/hr - 1.12 pint/hr or 26.8 pints/day
The SEZ system removes a lot more water, but the PEAD moves a lot more air. The return and supply duct runs will be 10-15’ with 10-12" flex or possible rigid round ducting, there will be some cfm loss due to ducting.
My thoughts, the SEZ system will move less air and require more time to cool the room, but will still refresh the 1056 cubic feet of air roughly every 3-5 minutes, is that enough? Because of the slower airflow, it will pull significantly more water out of the air when it is running. The PEAD moves enough air that it would circulate the 1056 cubic feet every 2-3 minutes, but is that too much? Because it moves air so quickly, it’s more likely to run shorter cycles and remove even less humidity.
Should I only worry about CFM and airflow with the AC? I will have a separate standalone dehumidifier, so should I just ignore the dehumidification levels and only focus on air volume? Let the ac cool and the dehumidifier pull water?