Selecting the proper 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 vital function in keeping its system running safely, efficiently and for a long time.
A dirty furnace filter loses its effectiveness, allowing potentially harmful particles to move through your home. It also limits airflow, which can damage your furnace and shorten its life span.
Ensuring your furnace uses a clean filter that is appropriate for your needs is not only about keeping your furnace running efficiently. It’s also about delivering good indoor air quality for your home.
The quality of the air your family breathes is important to the heating and cooling professionals at Air Masters Heating & Cooling. We've long been dedicated to bettering indoor air quality in Port Orchard. 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?
When Should I Replace My Furnace Air Filter?
It's important to replace dirty air filters in a furnace or air conditioner regularly. Dirt-clogged filters cause the system to worker harder than it should because it takes more energy to pull 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 it is dirty because it will be gray or black from dirt or dust. Homeowners who have pets that shed will likely have to replace their furnace air filter more often, because an effective 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 located in the return air duct or blower compartment before the return air gets to the furnace. This makes sure air being pulled into the system is filtered before it goes through the furnace components and is heated.
Depending on the type of furnace, the filter may be positioned on the right, left, bottom or in some cases, on the inside of the furnace. It's usually housed in a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for details concerning filter location of the furnace in your home.
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 air conditioner filter are basically the same. 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, making certain the air flowing through 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 choose 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 indicates the effectiveness of air filters at trapping airborne molecules. The rating scale ranges from 1 to 20, with greater numbers indicating the power to filter small particles.
Experts say a filter with a MERV rating between 8 and 13 offers a good balance between having adequate indoor air quality without needlessly restricting airflow. However, people with some health conditions may need to use a filter with a higher MERV rating.
How to Place the Air Filter in a Furnace or Air Conditioner
Putting an air filter in a furnace or air conditioner properly is crucial for the efficient operation of the system. Air filters have 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 air conditioning unit, which is the direction of the airflow. If you're doubtful about the airflow direction, try to remember that air always moves from the return duct towards the heat or cooling source. Therefore, make sure the arrow points toward the furnace or air conditioning unit.
Many people struggle with which direction to install their 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 point. A handy time to do this is during a routine furnace maintenance appointment.
Changing Your Furnace's Air Filter
Replacing the filter on your furnace or air conditioning system is an easy process. Here is a step-by-step rundown 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.
- Find the furnace filter: Typically, the filter is located in 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 similarly.
- Remove the old filter: Be careful not to knock out any dust or debris.
- 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 nicely and close any latches or clips that hold it in the compartment.
- Turn on your furnace: Once the replacement filter is properly installed, 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 air conditioner filter is one of the simplest things you can do to keep your system working efficiently.