The Daystar A/C is Hydrofarm's answer for those wanting high-performance coupled with maximum air cooling potential. Utilizing the same patented double-wall design and reflective material as the flagship Daystar unit, the "A/C" adds two 6" built-on flanges for cooling air flow from an optional fan. The 6" diameter encompasses most of the tunnel-like interior ensuring more complete air flow than common air-cooled units. This combination allows for closer plant placement plus better growth, and improved ability to control growing-area temperatures. 21" Long x 21" Wide x 9 3/8" Tall