28 Mar What Is A Blower Motor?(Last Updated On: March 28, 2017)
Definition of Blower Motor
A blower motor is the component within a home’s HVAC system that blows heated air through the vents when the heating system is in use. Some blower motors also blow cold air when the air conditioning system is in use. There are two main types of blower motors: single-speed motors and variable-speed motors. Single-speed blower motors blow air at one speed, whereas variable-speed blower motors can adjust their speed to blow air at varying speed levels. A properly functioning blower motor is a critical component to your home’s HVAC system and is vital in maintaining a comfortable temperature within your home.
How A Blower Motor Works
When the temperature in your home drops below what the thermostat is set to, it signals to the furnace that it’s time to get to work. The furnace creates hot (or cold) air, which then needs to make its way to the various rooms of your home. This is when the blower motor engages.
A blower motor takes the heated or cooled air created within the furnace and circulates it throughout the home in order to ensure the temperature reaches what’s called for on the thermostat. It does this by spinning a fan, which blows the air through the ventilation system of your home. Even a small blower motor can move a large volume of air.
Single-speed motors operate at one speed, and full energy capacity when in use. The thermostat is what tells your blower motor when to turn on and off. Because it only runs when heat is called for, a single-speed motor can result in cold spots being felt throughout your home. A variable-speed motor will blow air at higher and lower speeds, when appropriate, and can thus help to create a more even temperature throughout your home. Another benefit of a variable-speed blower motor is that they are often more energy efficient than a single-speed motor, which can help you save on your monthly energy bills.
Examples of Blower Motors
The most common example of a blower motor is the one that is found within forced air HVAC systems. A blower motor is also found vehicles, and is the part of that system responsible for pushing the hot air throughout your vehicle when you are running the heating system. It also blows through the vehicle’s AC evaporator in order to provide cool air when the air conditioning system is running.
Choosing A Blower Motor
When choosing a replacement blower motor for your furnace, it’s best to get an exact replacement unit. You can do this by finding the serial number on your blower motor and checking with the manufacturer to see if they have one available. If a replacement is not available, you can usually find a universal model that is compatible with your furnace. You will need to account for: type of drive, motor diameter, voltage, horsepower, speeds, rotation direction, size of the run capacitor (if required), and mounting method when shopping for a replacement blower motor.
The best person to help you choose and install the correct blower motor for your home’s heating and cooling system is a qualified HVAC professional.
Blower Motor Maintenance
One of the most hard-to-miss signs that your blower motor is no longer working is that your furnace is constantly running, but the house still feels cool. By properly maintaining your furnace’s blower motor, you can ensure your family’s year-round comfort. Before each heating season, ensure that the fan blades are cleaned, the motor belt is checked for wear and tear, and the motor is adequately lubricated.
Even with proper maintenance, there are some issues that can still cause your blower motor to stop working. The most common issues are seen with the resistor, fan relay, and climate control switches. These can all be evaluated by a qualified HVAC professional.
Blower motor failure can also be caused by a bearing wearing out, the motor breaking or wearing out, or the fan cage becoming obstructed. The motor itself can become dirty, and should be regularly cleaned. Because furnaces are typically installed in basements and laundry rooms, dirt and even small lint particles can make their way into the motor, causing burnouts. Obstruction of the blower motor fan cage can be caused by a buildup of dirt, or by debris that has fallen down the ventilation system, or has been placed there by a small animal.
Keeping the blower motor fan cage clean is essential to ensure proper operation of your HVAC system. This can easily be completed by a qualified HVAC professional and should be part of your regular annual furnace maintenance.