For nearly a century, Fasco has been producing and making what has become the industry's most respected line of AC motors and blowers. Many of the new energy-proficient gas furnaces use induced draft blowers to control flue gas. All induced draft blowers implement some type of signaling device to alert the furnace that the induced draft blower is operating. Some utilize a sail switch in the exhaust air stream. Others make use of a centrifugal switch or electronic sensor built into the motor, and some use a static pressure tap in the blower housing. All blowers are designated to give air flow prior to ignition. In today's furnace market, draft inducers are becoming a common replacement part. Since these furnaces are being designed with particular induced draft blowers, it is especially crucial that replacements are installed utilizing exact replacements.