Selecting the correct 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 vital part in keeping its system operating safely, efficiently and for a long time.
An overused furnace filter loses its effectiveness, allowing potentially harmful particles to flow through your home. It also limits airflow, which can damage your furnace and decrease its life span.
Making sure your furnace uses a clean filter that is ideal for your needs is not just about keeping your furnace working efficiently. It’s also about delivering excellent indoor air quality for your home.
The health of your family is important to the heating pros at Fire & Ice HVAC. We've long been dedicated to improving indoor air quality in Manassas. Here, we’ve answered common questions about HVAC filters, including that particularly 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 important to replace dirty air filters in a furnace or air conditioner regularly. Soiled filters cause the system to worker harder than it should because it takes more energy to move air through the plugged-up filter.
Officials recommend 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 be gray or black from dirt or dust. People who have pets that shed will likely have to replace their furnace air filter more often, because an effective 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 normally found in the return air duct or blower compartment before the return air reaches the furnace. This ensures air being pulled into the system is filtered before it passes through the furnace components and is heated.
Depending on the type of furnace, 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 important information concerning filter location of your particular brand and model of furnace.
Is a Furnace Filter the Same as an Air Filter?
The easy answer is, yes. In HVAC, a furnace filter and an air filter or air conditioning filter are effectively the same thing. While people may call them different things based on the current season— summer or winter—they are all filters that clean the air in your residence.
They each eliminate dust, allergens, bacteria and other airborne debris 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 Are MERV Ratings and What MERV Rating Should I Have?
Once you track down your old furnace filter and determine when it should be changed, it’s time to pick 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 is short 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 higher numbers indicating the power to filter small 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 Air Conditioner
Positioning an air filter in a furnace or air conditioner the proper way is necessary 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 installed with this arrow pointing in the direction of 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 and then to the heat or cooling source. Therefore, make certain the arrow points at the furnace or AC.
Many people have difficulty remembering which direction to face their air filter. To help remember, consider taking a quick picture with your cell 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 perfect time to inquire about this is during a scheduled furnace maintenance appointment.
How to Replace Your Furnace Air Filter
Changing the filter on your furnace or AC is a simple process. Here is a step-by-step breakdown of how to remove a dirty air filter and exchange it for a new one:
- Turn off your furnace: Be sure to shut off your furnace before starting the process.
- Look for the furnace filter: Typically, the filter is found within the furnace or in the air return vent. Take note of which direction the arrow points on the filter, because you’ll want the arrow on the replacement filter to point similarly.
- Take out the old filter: Be careful not to knock out any dust or particles.
- Note the date: Write down the date of replacement on the new filter's frame. This will help your family keep track of when it's time for another replacement.
- 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 securely and close any latches or clips that lock it in the unit.
- Turn on your furnace: Once the new filter is completely installed, you can turn your furnace back on.
Will a Dirty Air Filter Damage My Furnace?
The shortest answer is, yes, a dirty air filter can cause a furnace to cease working or reduce its lifespan. Changing your furnace or AC filter is one of the simplest things you can do to keep your system operating effectively.