Choosing the correct furnace filter and changing it when it gets dirty is as important to your HVAC system as changing the oil is to your car. Each plays a vital role in keeping its system running safely, efficiently and for a long time.
A clogged furnace filter loses its effectiveness, allowing potentially harmful particles to circulate through your home. It also limits airflow, which can damage your furnace and reduce its life span.
Making certain your furnace uses a clean filter that is ideal for your needs is not only about keeping your furnace working efficiently. It’s also about delivering excellent indoor air quality for your household.
The quality of the air your family breathes is important to the heating and cooling pros at The Chilly Pig. We've long worked with an eye on enhancing indoor air quality in Melbourne. Here, we’ve answered common questions about HVAC filters, including that especially 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
Experts stress it's important to replace dirty air filters in a furnace or air conditioner regularly. Dirty filters cause the system to worker harder than it should because it takes extra work to move air through the plugged-up filter.
Officials suggest examining your furnace filter every 30 days and replacing it if it’s dirty. You’ll know if the filter needs to be changed because it will coated with dirt or dust. Those who have pets that shed 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 usually found 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 passes through the furnace components and is heated.
Depending on the furnace brand, the filter may be found on the right, left, bottom or in some cases, within 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 information concerning filter location of your particular brand and model of furnace.
Is My Furnace Filter Just a Type of Air Filter?
The easy answer is, yes. In HVAC, a furnace filter and an air filter or air conditioner filter are effectively the same. While they might be called different things based on the current season— hot or cold—they are all filters that clean the air in your HVAC system.
They each remove dust, allergens, bacteria and other contaminants from the air that is drawn into the furnace and air conditioning system, ensuring the air distributed throughout your home is clean and safe.
What Is the MERV Rating System and What MERV Rating Do I Need?
Once you track down your old furnace filter and decide when it should be replaced, it’s time to pick a replacement. That means determining the level of filtration that you need. One approach to this is by picking an appropriate MERV rating for your needs.
MERV is an abbreviation for Minimum Efficiency Reporting Values. The MERV rating indicates the effectiveness of air filters at trapping airborne particles. The rating scale ranges from 1 to 20, with higher numbers indicating enhanced capabilities to filter smaller particles.
Experts say a filter with a MERV rating between 8 and 13 offers a good balance between having good indoor air quality without overly restricting airflow. However, people with some health conditions might need a a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or AC Unit
Installing an air filter in a furnace or air conditioner the proper way is important for the efficient operation of the system. Air filters are designed to be installed in a particular direction, indicated by an arrow written on the side of the filter frame. The filter should be put in with this arrow pointing at the furnace or AC, which is the direction of the airflow. If you're not sure about the airflow direction, remember that air always moves from the return duct and then to the heat or cooling source. Therefore, make sure the arrow points toward the furnace or air conditioning unit.
Many people have difficulty remembering which direction to point their system's air filter. To help remember, consider taking a quick picture with your cellular phone after the filter has been properly 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 point. A handy time to do this is during a routine furnace maintenance appointment.
Changing Your Furnace's Air Filter
Replacing the filter on your furnace or AC is a simple process. Here is a step-by-step rundown of how to take out a dirty air filter and replace it with a new one:
- Turn off your furnace: Make sure 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 a mental note or write down which direction the arrow points on the filter, because you’ll want the arrow on the replacement filter to point in the same direction.
- Take out the old filter: Be diligent not to knock out any dust or particles.
- Record the date: Write down the date you replaced the filter on the new filter's frame. This will help you keep track of when it's time for the next change.
- Put in 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 your last filter.
- Secure the filter: Make sure the new filter fits correctly and close any latches or clips that secure it in the compartment.
- Turn on your furnace: Once the clean filter is completely installed, you can turn your furnace back on.
Can a Dirty Air Filter Cause Problems for a Furnace?
The simple answer is, yes, a dirty air filter can cause a furnace to cease working or shorten its lifespan. Changing your furnace or AC filter is one of the simplest things you can do to keep your system operating effectively.