I have a 16x16x8 well-insulated room with an ATMOS-B2 Basic Digital Atmosphere Controller, 20 gal co2 tank (used occasionally), a 780 cfm inline fan for 3 vented/insulated 600w well-sealed hps fixtures. I also have a 30,000 BTU nat. gas space heater for winter, an 8000 BTU a/c through the wall...