Picking out the correct 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 flow through your home. It also limits airflow, which can damage your furnace and reduce its life span.
Making certain your furnace uses a clean filter that is suitable for your needs is not just about keeping your furnace running efficiently. It’s also about providing excellent indoor air quality for your residence.
The quality of the air your family breathes is important to the HVAC professionals at Strine's. We've long worked with an eye on bettering indoor air quality in York. 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?
When Should I Replace My Furnace Air Filter?
Experts stress it's important 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 work to move air through the plugged-up filter.
Officials suggest inspecting your furnace filter monthly and replacing it if it’s dirty. You’ll know if it is dirty because it will be gray or black from dirt or dust. People who have dogs and cats 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 commonly located in the return air duct or blower compartment before the return air reaches the furnace. This makes sure air entering the system is filtered before it moves through the furnace components and is heated.
Depending on the type of furnace, the filter may be located on the right, left, bottom or in some cases, within 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 important information regarding filter location of your particular brand and model of furnace.
Is My Furnace Filter Just a Type of Air Filter?
The easy answer is, yes. In HVAC, a furnace filter and an air filter or air conditioner filter are basically identical. 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 remove dust, allergens, bacteria and other airborne debris 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 a MERV Rating and What MERV Rating Should I Have?
Once you track down your old furnace filter and determine when it should be substituted for a clean one, it’s time to select a replacement. That means deciding on the level of filtration that you need. One method to do this is by picking an appropriate MERV rating for your needs.
MERV is an abbreviation for Minimum Efficiency Reporting Values. The MERV rating calculates the effectiveness of air filters at trapping airborne contaminants. 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 good indoor air quality without overly restricting airflow. However, people with specific health conditions could need to use a filter with a higher MERV rating.
How to Place the Air Filter in a Furnace or AC Unit
Putting an air filter in a furnace or air conditioner properly is necessary for the efficient operation of the unit. Air filters are supposed to face a specific direction, indicated by an arrow printed on the side of the filter frame. The filter should be placed in the unit with this arrow pointing at the furnace or air conditioning unit, which is the direction of the airflow. If you're not sure about the airflow direction, remember that air always moves from the return duct towards the heat or cooling source. Therefore, make sure the arrow points in the direction of the furnace or air conditioner.
Many people are confused by which direction to face an air filter. To help remember, consider taking a quick picture with your cell 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 ask about this is during a regular furnace maintenance visit.
Changing Your Furnace's Air Filter
Switching out the filter on your furnace or air conditioning system is a quick and easy process. Here is a step-by-step list of how to retreive a dirty air filter and exchange it for a new one:
- Turn off your furnace: Make a point to switch off your furnace before starting up the process.
- Locate the furnace filter: Typically, the filter is positioned inside 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 new filter to point the same way.
- Slide out the old filter: Be mindful not to knock out any dust or debris.
- 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 you to change it again.
- Insert new filter: Put in the new filter with the arrow pointing in the direction of 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 hold it in the unit.
- Turn on your furnace: Once the clean filter is completely secured, you can turn your furnace back on.
Will 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 limit its lifespan. Changing your furnace or AC filter is one of the easiest things you can do to keep your system running correctly.