Blower Fan Motors take the return air from your home and disperse it through the duct system to increase efficiency and keep the furnace from getting too hot. They are placed inside the furnace or air handler. Blower motors consist of a motor and impeller. The airflow is blasted when the HVAC system is turned on. They range in power from about 1/8 to 3/4 horsepower and typically have a 1,200 RPM. Motors come in many different types, such as split phase and three-phase. Replacing a blower motor may be a difficult job even for someone who is experienced at doing these things themselves. It can be tough to identify and install the right size fan. A good rule of thumb is if you could install an electric motor into a ceiling fan or some other electrical device, you can probably handle a furnace blower motor as well. If not, consider hiring a qualified HVAC company to install the fan.