The camera does not have sufficient information to tell you why or how the circulating blower works. Although it gives great video (somewhat blurred) in daylight it also gives good video in color at night for a very good distance these attributes cannot be overcome by the large size and the fact that it requires the power source (110 outlet) where the camera is located. Power cannot be supplied over a dual wire cable similar to other Q-See cameras. Would not recommend due to size and power requirement.