Choosing the proper 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 vital role in keeping its system operating safely, efficiently and for a long time.
An overused furnace filter loses its effectiveness, permitting potentially harmful particles to circulate through your home. It also slows airflow, which can damage your furnace and shorten its life span.
Making certain your furnace uses a clean filter that is appropriate for your needs is not merely about keeping your furnace working efficiently. It’s also about providing good indoor air quality for your household.
The health of your family is important to the heating professionals at Gilray Heating and Cooling. We've long focused on improving indoor air quality in Wausau. 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 critical 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 recommend checking 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 filled with dirt or dust. Homeowners who have pets that shed will very likely have to replace their furnace air filter more often, because an effective air filter will trap pet hair circulating in a home.
Where Is the Air Filter in My Furnace?
In general, a furnace air filter is normally 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 goes through the furnace components and is heated.
Depending on the furnace model, 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 easy access and replacement. Always refer to your furnace's owner manual for information regarding filter location of the furnace in your home.
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 air conditioning filter are basically the same. 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 residence.
They each get rid of dust, allergens, bacteria and other particulates 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 a MERV Rating and What Rating Is Best for Me?
Once you locate your old furnace filter and determine when it should be changed, it’s time to pick a replacement. That means picking the level of filtration that you need. One approach to this is by picking 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 a greater ability to filter smaller particles.
Experts say a filter with a MERV rating between 8 and 13 offers an ideal balance between having healthy indoor air quality without needlessly restricting airflow. However, people with some health conditions might need a a higher MERV rating.
Where to Insert the Air Filter in a Furnace or AC Unit
Putting an air filter in a furnace or air conditioner correctly is necessary for the efficient operation of the unit. Air filters are designed to be installed in a certain 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 in the direction of the furnace or air conditioning unit, which is the direction of the airflow. If you're unsure 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 at the furnace or air conditioner.
Many people are confused by which direction to face their air filter. To help remember, consider snapping a quick photo with your cellular 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 inquire about this is during a scheduled furnace maintenance appointment.
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 retreive a dirty air filter and exchange it for a new one:
- Turn off your furnace: Be sure to switch off your furnace before starting the process.
- Locate the furnace filter: Typically, the filter is located 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 new filter to point similarly.
- Slide out the old filter: Be mindful not to knock out any dust or particles.
- Document the date: Write down the date you changed filters on the new filter's frame. This will make it easier to 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 your last filter.
- Secure the filter: Make sure the new filter fits securely and close any latches or clips that secure it in place.
- Turn on your furnace: Once the clean filter is properly in place, 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 reduce its lifespan. Changing your furnace or air conditioning filter is one of the best things you can do to keep your system running effectively.