Selecting the right 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 crucial function in keeping its system working safely, efficiently and for a long time.
A clogged furnace filter loses its effectiveness, permitting potentially harmful particles to circulate through your home. It also restricts airflow, which can damage your furnace and reduce its life span.
Ensuring your furnace uses a clean filter that is appropriate for your needs is not only about keeping your furnace operating efficiently. It’s also about providing excellent indoor air quality for your household.
The health of your family is important to the heating and cooling professionals at Bishop Heating & Air Conditioning. We've long been dedicated to bettering indoor air quality in Bishop. Here, we’ve answered frequent questions about HVAC filters, including that very tricky question of what direction do you point a filter in your furnace or air conditioner?
When Should I Replace My Furnace Air Filter?
It is vital to replace dirty air filters in a furnace or air conditioner routinely. Soiled filters cause the system to worker harder than it should because it takes extra effort to force air through the plugged-up filter.
Officials recommend examining your furnace filter monthly and replacing it if it’s dirty. You’ll know if the filter needs to be changed because it will be gray or black from dirt or dust. Those who have pets that shed will very likely want 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 commonly found in the return air duct or blower compartment before the return air reaches the furnace. This is so air being pulled into the system is filtered before it moves through the furnace components and is heated.
Depending on the type of furnace, the filter may be positioned on the right, left, bottom or in some cases, within the furnace. It's typically housed in a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for details concerning filter location of your 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 AC filter are effectively the same thing. While they might be called different things based on the current season— summer or winter—they are all filters that clean the air in your home.
They each eliminate dust, allergens, bacteria and other particulates 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 the MERV Rating System and What Rating Is Best for Me?
Once you track down your old furnace filter and determine when it should be changed, it’s time to select a replacement. That means determining the level of filtration that you need. One approach to this is by choosing an appropriate MERV rating for your needs.
MERV stands for Minimum Efficiency Reporting Values. The MERV rating calculates the effectiveness of air filters at trapping airborne particles. The rating scale ranges from 1 to 20, with bigger numbers indicating enhanced capabilities to filter tinier particles.
Experts say a filter with a MERV rating between 8 and 13 offers a good balance between having good indoor air quality without unnecessarily restricting airflow. However, people with some health conditions might need a a higher MERV rating.
How to Place 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 unit. Air filters have a specific direction, indicated by an arrow located on the side of the filter frame. The filter should be put in with this arrow pointing toward the furnace or air conditioning unit, which is the direction of the airflow. If you're doubtful about the airflow direction, remember that air always moves from the return duct towards the heat or cooling source. Therefore, make certain the arrow points in the direction of the furnace or AC.
Many people have difficulty remembering which direction to face an air filter. To help remember, consider snapping a quick photo 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 great time to inquire about this is during a routine furnace maintenance visit.
Changing Your Furnace's Air Filter
Switching out the filter on your furnace or air conditioner is a quick and easy process. Here is a step-by-step rundown of how to remove a dirty air filter and exchange it for a new one:
- Turn off your furnace: Make sure to turn off your furnace before starting the process.
- Find the furnace filter: Typically, the filter is positioned in 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 clean filter to point similarly.
- Slide out the old filter: Be careful not to knock out any dust or dirt.
- Note the date: Write down the date you changed filters on the new filter's frame. This will help your family keep track of when it's time for another replacement.
- Insert new filter: Put in the new filter with the arrow pointing toward 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 securely and close any latches or clips that hold it in place.
- Turn on your furnace: Once the replacement filter is completely secured, you can turn your furnace back on.
Can a Dirty Air Filter Cause a Furnace Not to Work?
The shortest answer is, yes, a dirty air filter can cause a furnace to quit working or shorten its lifespan. Changing your furnace or AC filter is one of the best things you can do to keep your system operating efficiently.