Selecting the right 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 critical role in keeping its system working safely, efficiently and for a long time.
An overused furnace filter loses its effectiveness, allowing potentially harmful particles to circulate through your home. It also restricts airflow, which can damage your furnace and reduce its life span.
Making sure your furnace uses a clean filter that is appropriate for your needs is not just about keeping your furnace running efficiently. It’s also about delivering excellent indoor air quality for your household.
The health of your family is important to the heating and cooling pros at Franklin's Heating & Air Conditioning, Inc. We've long worked with an eye on bettering indoor air quality in Oxford. 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's vital to replace dirty air filters in a furnace or air conditioner periodically. Dirty 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 checking your furnace filter every 30 days and replacing it if it’s dirty. You’ll know if your filter needs changing because it will filled with dirt or dust. Those who have pets that shed will very likely want to replace their furnace air filter more often, because a quality 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 found in the return air duct or blower compartment before the return air goes back into the furnace. This makes sure air flowing into the system is filtered before it goes 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, on the inside of the furnace. It's generally housed in a slot, frame or cabinet for simple access and replacement. Always refer to your furnace's owner manual for details about filter location of the furnace in your home.
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 essentially the same. While people might refer to them differently based on the current season— summer or winter—they are all filters that clean the air in your residence.
They each remove dust, allergens, bacteria and other particulates 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 Do I Need?
Once you find 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 way to do that is by picking an appropriate MERV rating for your needs.
MERV is an abbreviation for Minimum Efficiency Reporting Values. The MERV rating measures the effectiveness of air filters at trapping airborne contaminants. The rating scale ranges from 1 to 20, with bigger numbers indicating enhanced capabilities to filter small particles.
Experts say a filter with a MERV rating between 8 and 13 offers an appropriate balance between having good indoor air quality without unnecessarily restricting airflow. However, people with certain health conditions may need to purchase a filters with a higher MERV rating.
How to Place the Air Filter in a Furnace or Air Conditioning System
Positioning an air filter in a furnace or air conditioner correctly is crucial for the efficient operation of the heating or cooling system. 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 put in with this arrow pointing in the direction of the furnace or AC, which is the direction of the airflow. If you're doubtful about the airflow direction, remember that air always moves from the return duct to the heat or cooling source. Therefore, make certain the arrow points in the direction of the furnace or air conditioning unit.
Many people have difficulty remembering 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 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 be installed. A handy time to inquire about this is during a regular furnace maintenance visit.
How to Change a Furnace Air Filter
Replacing the filter on your furnace or AC is a simple process. Here is a step-by-step breakdown of how to take out a dirty air filter and swap it for a new one:
- Turn off your furnace: Make a point to turn off your furnace before starting up the process.
- Locate the furnace filter: Typically, the filter is found 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 replacement filter to point in the same direction.
- Slide out the old filter: Be mindful 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 make it easier to keep track of when it's time for you to change it again.
- Slide in 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 correctly and close any latches or clips that secure it in the compartment.
- Turn on your furnace: Once the new filter is safely installed, you can turn your furnace back on.
Will a Dirty Air Filter Cause a Furnace Not to Work?
The short answer is, yes, a dirty air filter can cause a furnace to cease 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 correctly.