Picking out the ideal furnace filter and changing it when it gets dirty is as important to your HVAC system as changing the oil is to your car. Each plays a crucial role in keeping its system running 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 slows airflow, which can damage your furnace and shorten its life span.
Making certain your furnace uses a clean filter that is suitable for your needs is not only about keeping your furnace operating efficiently. It’s also about providing good indoor air quality for your residence.
The quality of the air your family breathes is important to the heating pros at AZ Air Conditioning and Heating. We've long focused on improving indoor air quality in Los Angeles. Here, we’ve answered common questions about HVAC filters, including that especially 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 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 more energy to move air through the plugged-up filter.
Officials suggest 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. Homeowners who have pets will very likely have to replace their furnace air filter more often, because a quality 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 usually installed in the return air duct or blower compartment before the return air gets to the furnace. This is so air entering the system is filtered before it passes 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, inside the furnace. It's usually housed inside of a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for information concerning filter location of your furnace.
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 AC 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, making certain the air circulating throughout your home is clean and safe.
What Is a MERV Rating and What Rating Is Best for Me?
Once you track down your old furnace filter and determine when it should be replaced, it’s time to choose a replacement. That means picking the level of filtration that you need. One method to do this is by choosing an appropriate MERV rating for your needs.
MERV is an abbreviation for Minimum Efficiency Reporting Values. The MERV rating indicates the effectiveness of air filters at trapping airborne molecules. 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 appropriate balance between having good indoor air quality without needlessly restricting airflow. However, people with certain health conditions could need to purchase a filters with a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or Air Conditioner
Positioning an air filter in a furnace or air conditioner correctly is necessary for the efficient operation of the system. Air filters are supposed to face a particular 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 in the direction of the furnace or air conditioning unit, which is the direction of the airflow. If you're not sure about the airflow direction, try to remember that air always moves from the return duct and then to the heat or cooling source. Therefore, make sure the arrow points in the direction of the furnace or air conditioning unit.
Many people struggle with which direction to install an air filter. To help remember, consider taking a quick picture with your cell 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 regular furnace maintenance visit.
Changing Your Furnace's Air Filter
Changing the filter on your furnace or air conditioning system 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: Be sure to switch off your furnace before starting the process.
- Look for the furnace filter: Typically, the filter is found 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 replacement filter to point in the same direction.
- Slide out 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 help your family 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 your last filter.
- 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 clean filter is completely secured, you can turn your furnace back on.
Can 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 shorten its lifespan. Changing your furnace or AC filter is one of the easiest things you can do to keep your system running efficiently.