All cobs produce heat, 80-85 degrees Fahrenheit is normal range. If your area gets hotter than 80 to 85 you may need additional cooling. Otherwise inline fan for heat removal and a recirculating fan should do fine. The lower the amperage you run, the les heat you create that has to be removed with fans. example cobs run at 700mA run much cooler than cobs run at 1400mA and 2100mA are twice as hot as 1400mA. It is not l;inear, it is a function of efficiency, the higher the amperage the less efficient the light is created and the more heat is created.