Picking out the right 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 function in keeping its system operating safely, efficiently and for a long time.
An overused furnace filter loses its effectiveness, enabling potentially harmful particles to circulate 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 appropriate for your needs is not just about keeping your furnace working efficiently. It’s also about creating healthy indoor air quality for your household.
Your health is important to the heating professionals at Covington Air Systems. We've long worked with an eye on improving indoor air quality in Covington. Here, we’ve answered frequent questions about HVAC filters, including that especially 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's 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 extra effort to move air through the plugged-up filter.
Officials recommend inspecting 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 filled with dirt or dust. Those who have pets that shed will very 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 normally installed in the return air duct or blower compartment before the return air gets to the furnace. This ensures air flowing into the system is filtered before it passes through the furnace components and is heated.
Depending on the furnace model, the filter may be located on the right, left, bottom or in some cases, on the inside of the furnace. It's typically housed in a slot, frame or cabinet for simple access and replacement. Always refer to your furnace's owner manual for facts regarding filter location of the furnace in your home.
Are Air Filters and Furnace Filters the Same Thing?
The straightforward answer is, yes. In HVAC, a furnace filter and an air filter or air conditioner filter are effectively identical. While people might refer to them differently based on the current season— hot or cold—they are all filters that clean the air in your home.
They each eliminate dust, allergens, bacteria and other contaminants from the air that is drawn into the furnace and air conditioning system, making certain the air flowing through your home is clean and safe.
What Is the MERV Rating System and What MERV Rating Should I Have?
Once you find your old furnace filter and determine when it should be changed, it’s time to select a replacement. That means picking the level of filtration that you need. One way to do that 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 molecules. The rating scale ranges from 1 to 20, with bigger numbers indicating the power to filter tinier particles.
Experts say a filter with a MERV rating between 8 and 13 offers a good balance between having adequate indoor air quality without overly restricting airflow. However, people with some health conditions might need to purchase a filters with a higher MERV rating.
Where to Insert the Air Filter in a Furnace or AC Unit
Positioning an air filter in a furnace or air conditioner correctly is necessary for the efficient operation of the heating or cooling system. Air filters have a particular direction, indicated by an arrow located 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 conditioner, which is the direction of the airflow. If you're doubtful about the airflow direction, it may be helpful to remember that air always moves from the return duct to the heat or cooling source. Therefore, make sure the arrow points at the furnace or air conditioning unit.
Many people have difficulty remembering which direction to install an air filter. To help remember, consider taking a 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 go. A handy time to inquire about this is during a regular 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 list of how to take out a dirty air filter and swap it for a new one:
- Turn off your furnace: Make sure to turn off your furnace before beginning the process.
- Look for the furnace filter: Typically, the filter is located in 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 the same way.
- Remove the old filter: Be careful 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 make it easier to keep track of when it's time for the next change.
- Slide 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 old filter you are replacing.
- Secure the filter: Make sure the new filter fits securely and close any latches or clips that secure it in the unit.
- Turn on your furnace: Once the replacement filter is completely installed, you can turn your furnace back on.
Will a Dirty Air Filter Cause a Furnace Not to Work?
The simple answer is, yes, a dirty air filter can cause a furnace to stop working or limit its lifespan. Changing your furnace or air conditioning filter is one of the best things you can do to keep your system working correctly.