We came across a series of articles entitled “Pro Tips,” (originally posted by General Hydroponics) that offer a great deal of insight into the art of hydroponic growing. So we thought we’d share this wealth of information with those of you looking to take your hydroponic growing skills to the next level. Enjoy!

If you are debating whether or not you need an air conditioner, chances are the answer is: YES YOU DO. A hot, humid grow room is a bad grow room.

An AC’s cooling ability is rated either by BTU or tonnage. 12,000 BTU’s = 1 ton.

A general rule of thumb is that for every 1 watt of HPS light, the end user will need 3 BTU’s of cooling power. Personally, I always go 20% over this to amount to account for environmental fluxes.

Thus a grower running 4x 1000 Watt HPS lights will need a minimum of 14,400 BTU’s of cooling.

So The formula is: (3 BTU’s) X (1.2) X (total watts of HPS light) = total BTU’s of AC needed.

If you are right at the edge, always size up rather than down.