Selecting the ideal furnace filter and changing it when it becomes dirty is as important to your HVAC system as changing the oil is to your car. Each plays a crucial role in keeping its system working safely, efficiently and for a long time.
A dirty furnace filter loses its effectiveness, permitting potentially harmful particles to flow through your home. It also slows airflow, which can damage your furnace and shorten its life span.
Making sure your furnace uses a clean filter that is suitable for your needs is not just about keeping your furnace working efficiently. It’s also about providing excellent indoor air quality for your residence.
Your health is important to the heating and cooling pros at Home Comfort Heating & Air. We've long been dedicated to enhancing indoor air quality in Elk River. Here, we’ve answered common questions about HVAC filters, including that very tricky question of what direction do you point a filter in your furnace or air conditioner?
When to Replace the Air Filter in Your Furnace
Experts stress it's vital 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 effort to pull air through the plugged-up filter.
Officials suggest examining your furnace filter every month 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. Homeowners who have pets that shed will likely need to replace their furnace air filter more often, because a good air filter will trap pet hair circulating in a home.
How to Find the Furnace's Air Filter
In general, a furnace air filter is usually located in the return air duct or blower compartment before the return air gets to the furnace. This is so air entering the system is filtered before it passes through the furnace components and is heated.
Depending on the furnace model, the filter may be positioned on the right, left, bottom or in some cases, inside the furnace. It's typically housed within a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for details regarding filter location of your furnace.
Is My Furnace Filter Just a Type of Air Filter?
The simple answer is, yes. In HVAC, a furnace filter and an air filter or AC filter are essentially 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 airborne debris from the air that is drawn into the furnace and air conditioning system, ensuring the air flowing through your home is clean and safe.
What Is a MERV Rating and What Rating Is Best for Me?
Once you locate your old furnace filter and decide when it should be changed, it’s time to select a replacement. That means picking the level of filtration that you need. One method to do this is by picking 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 particles. The rating scale ranges from 1 to 20, with bigger numbers indicating a greater ability 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 could need to use a filter with a higher MERV rating.
How to Place the Air Filter in a Furnace or Air Conditioning System
Installing an air filter in a furnace or air conditioner properly is important for the efficient operation of the system. Air filters are supposed to face a certain direction, indicated by an arrow written on the side of the filter frame. The filter should be installed with this arrow pointing in the direction of the furnace or air conditioner, which is the direction of the airflow. If you're unsure about the airflow direction, remember that air always moves from the return duct and then to the heat or cooling source. Therefore, be sure that the arrow points toward the furnace or air conditioning unit.
Many people struggle with which direction to face their system's air filter. To help remember, consider taking a quick picture with your cell phone after the filter has been accurately 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 great time to do this is during a routine furnace maintenance visit.
How to Change a Furnace Air Filter
Replacing the filter on your furnace or air conditioner is an easy process. Here is a step-by-step breakdown of how to remove a dirty air filter and replace it with a new one:
- Turn off your furnace: Be sure to turn off your furnace before beginning the process.
- Locate the furnace filter: Typically, the filter is located inside 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 the same way.
- Slide out the old filter: Be diligent not to knock out any dust or dirt.
- Note the date: Write down the date you replaced the filter on the new filter's frame. This will help your family keep track of when it's time for the next change.
- Put in new filter: Put in the new filter with the arrow pointing at the furnace, which is the direction of airflow and should be the same direction the arrow pointed on the dirty filter you just removed.
- Secure the filter: Make sure the new filter fits correctly and close any latches or clips that secure it in the unit.
- Turn on your furnace: Once the new filter is safely secured, you can turn your furnace back on.
Can a Dirty Air Filter Cause Problems for a Furnace?
The short answer is, yes, a dirty air filter can cause a furnace to stop working or reduce its lifespan. Changing your furnace or air conditioner filter is one of the best things you can do to keep your system working efficiently.
