Picking out 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 function in keeping its system operating safely, efficiently and for a long time.
An overused furnace filter loses its effectiveness, permitting potentially harmful particles to flow through your home. It also slows airflow, which can damage your furnace and shorten its life span.
Making sure your furnace uses a clean filter that is ideal for your needs is not only about keeping your furnace running efficiently. It’s also about delivering good indoor air quality for your residence.
The quality of the air your family breathes is important to the heating and cooling pros at Interstate Heating & Air Conditioning. We've long been dedicated to enhancing indoor air quality in Omaha. Here, we’ve answered frequent questions about HVAC filters, including that very tricky question of what direction do you point a filter in your furnace or air conditioner?
When to Replace the Air Filter in Your Furnace
Experts stress 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 examining your furnace filter monthly 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 dogs and cats will likely want 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 commonly located 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 moves 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 typically housed within 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 particular brand and model of furnace.
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 the same thing. While people may call them different things based on the current season— hot or cold—they are all filters that clean the air in your HVAC system.
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 Is a MERV Rating and What MERV Rating Do I Need?
Once you find your old furnace filter and figure out when it should be replaced, it’s time to choose 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 molecules. The rating scale ranges from 1 to 20, with bigger numbers indicating enhanced capabilities to filter smaller particles.
Experts say a filter with a MERV rating between 8 and 13 offers an ideal balance between having healthy indoor air quality without overly restricting airflow. However, people with specific health conditions may need to purchase a filters with a higher MERV rating.
Where to Insert the Air Filter in a Furnace or AC Unit
Putting an air filter in a furnace or air conditioner the proper way 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 toward 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 towards the heat or cooling source. Therefore, make sure the arrow points at the furnace or air conditioner.
Many people struggle with which direction to face their system's air filter. To help remember, consider taking a 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 point. A handy time to inquire about this is during a routine furnace maintenance appointment.
Changing Your Furnace's Air Filter
Switching out the filter on your furnace or air conditioner is a quick and easy process. Here is a step-by-step breakdown of how to take out a dirty air filter and exchange it for a new one:
- Turn off your furnace: Make a point to turn off your furnace before starting the process.
- Look for the furnace filter: Typically, the filter is located inside 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 clean filter to point the same way.
- Slide out the old filter: Be mindful not to knock out any dust or particles.
- Note the date: Write down the date you changed filters on the new filter's frame. This will help your family keep track of when it's time for you to change it again.
- 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 old filter you are replacing.
- Secure the filter: Make sure the new filter fits correctly and close any latches or clips that hold it in the compartment.
- Turn on your furnace: Once the new filter is completely installed, you can turn your furnace back on.
Can a Dirty Air Filter Cause Problems for a Furnace?
The short 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 easiest things you can do to keep your system running efficiently.