Selecting the right furnace filter and changing it when it is dirty is as important to your HVAC system as changing the oil is to your car. Each plays a crucial function in keeping its system running safely, efficiently and for a long time.
An overused furnace filter loses its effectiveness, allowing potentially harmful particles to circulate through your home. It also restricts airflow, which can damage your furnace and decrease its life span.
Ensuring your furnace uses a clean filter that is suitable for your needs is not only about keeping your furnace operating efficiently. It’s also about providing healthy indoor air quality for your residence.
The quality of the air your family breathes is important to the heating and cooling pros at Kapaun & Brown. We've long worked with an eye on enhancing indoor air quality in Marshalltown. Here, we’ve answered frequent questions about HVAC filters, including that particularly tricky question of what direction do you point a filter in your furnace or air conditioner?
How Often to Replace the Air Filter in a Furnace
It is important to replace dirty air filters in a furnace or air conditioner routinely. Dirty filters cause the system to worker harder than it should because it takes extra work to force air through the plugged-up filter.
Officials suggest inspecting your furnace filter every month and replacing it if it’s dirty. You’ll know if it is dirty because it will filled with dirt or dust. Homeowners who have dogs and cats will likely want to replace their furnace air filter more often, because a quality air filter will trap pet hair circulating in a home.
Locating Your Furnace's Air Filter
In general, a furnace air filter is commonly located in the return air duct or blower compartment before the return air goes back into the furnace. This ensures air flowing into the system is filtered before it goes through the furnace components and is heated.
Depending on the type of furnace, the filter may be located on the right, left, bottom or in some cases, inside the furnace. It's typically housed inside of a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for important information concerning filter location of your particular brand and model of furnace.
Are Air Filters and Furnace Filters the Same Thing?
The easy answer is, yes. In HVAC, a furnace filter and an air filter or air conditioning filter are basically the same thing. While they might be called different things based on the current season— warm or chilly months—they are all filters that clean the air in your HVAC system.
They each remove dust, allergens, bacteria and other particulates from the air that is drawn into the furnace and air conditioning system, ensuring the air circulating throughout your home is clean and safe.
What Is the MERV Rating System and What Rating Is Best for Me?
Once you find your old furnace filter and determine when it should be changed, it’s time to choose a replacement. That means deciding on the level of filtration that you need. One method to do this is by choosing an appropriate MERV rating for your needs.
MERV stands for Minimum Efficiency Reporting Values. The MERV rating indicates the effectiveness of air filters at trapping airborne contaminants. The rating scale ranges from 1 to 20, with greater numbers indicating a greater ability to filter small particles.
Experts say a filter with a MERV rating between 8 and 13 offers an appropriate balance between having adequate indoor air quality without needlessly restricting airflow. However, people with certain health conditions might need to purchase a filters with a higher MERV rating.
Where to Insert the Air Filter in a Furnace or AC Unit
Positioning an air filter in a furnace or air conditioner properly is necessary for the efficient operation of the heating or cooling system. Air filters are supposed to face a specific direction, indicated by an arrow written on the side of the filter frame. The filter should be placed in the unit with this arrow pointing toward the furnace or AC, which is the direction of the airflow. If you're not sure about the airflow direction, it may be helpful to remember that air always moves from the return duct towards the heat or cooling source. Therefore, be sure that the arrow points in the direction of the furnace or AC.
Many people are confused by which direction to install their system's air filter. To help remember, consider taking a quick picture with your cellular phone after the filter has been correctly installed by a professional. Or, you also could ask a technician to use a marker to write on the outside of your furnace which direction the filter should go. A perfect time to ask about this is during a scheduled furnace maintenance appointment.
How to Change a Furnace Air Filter
Replacing the filter on your furnace or air conditioning system is a quick and easy process. Here is a step-by-step rundown of how to remove a dirty air filter and swap it for a new one:
- Turn off your furnace: Make a point to shut off your furnace before beginning the process.
- Locate the furnace filter: Typically, the filter is positioned within the furnace or in the air return vent. Make note of which direction the arrow points on the filter, because you’ll want the arrow on the clean filter to point similarly.
- Remove the old filter: Be mindful not to knock out any dust or debris.
- Document the date: Write down the date you replaced the filter on the new filter's frame. This will make it easier to keep track of when it's time for you to change it again.
- Insert new filter: Put in the new filter with the arrow pointing in the direction of the furnace, which is the direction of airflow and should be the same direction the arrow pointed on the old filter you are replacing.
- Secure the filter: Make sure the new filter fits correctly and close any latches or clips that lock it in place.
- Turn on your furnace: Once the clean filter is properly installed, you can turn your furnace back on.
Can a Dirty Air Filter Damage My Furnace?
The simple answer is, yes, a dirty air filter can cause a furnace to cease working or decrease its lifespan. Changing your furnace or air conditioner filter is one of the simplest things you can do to keep your system operating effectively.