Selecting 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 critical part in keeping its system working 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 slows airflow, which can damage your furnace and reduce its life span.
Making sure your furnace uses a clean filter that is suitable for your needs is not merely about keeping your furnace working efficiently. It’s also about providing healthy indoor air quality for your household.
The health of your family is important to the heating professionals at Freed Heating & Air Conditioning. We've long focused on enhancing indoor air quality in Moline. 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 Should I Replace My Furnace Air Filter?
It's critical 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 extra effort to pull air through the plugged-up filter.
Officials recommend inspecting your furnace filter monthly and replacing it if it’s dirty. You’ll know if your filter needs changing because it will be gray or black from dirt or dust. Those who have dogs and cats will probably need to replace their furnace air filter more often, because a good air filter will trap pet hair circulating in a home.
Locating Your Furnace's Air Filter
In general, a furnace air filter is normally found in the return air duct or blower compartment before the return air goes back into the furnace. This ensures 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, 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 about 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 essentially identical. While people might refer to them differently based on the current season— warm or chilly months—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 flowing through your home is clean and safe.
What Is a MERV Rating and What MERV Rating Do I Need?
Once you track down your old furnace filter and figure out when it should be substituted for a clean one, it’s time to choose 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 measures the effectiveness of air filters at trapping airborne molecules. The rating scale ranges from 1 to 20, with greater numbers indicating a greater ability to filter small particles.
Experts say a filter with a MERV rating between 8 and 13 offers a good balance between having healthy indoor air quality without needlessly restricting airflow. However, people with specific health conditions may need a a higher MERV rating.
Which Way to Put 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 unit. Air filters have a certain direction, indicated by an arrow written on the side of the filter frame. The filter should be placed in the unit 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, try to remember that air always moves from the return duct to the heat or cooling source. Therefore, be sure that the arrow points toward the furnace or air conditioner.
Many people have difficulty remembering which direction to point an air filter. To help remember, consider taking a picture with your mobile 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 be installed. A handy time to do this is during a scheduled furnace maintenance appointment.
How to Replace Your Furnace Air Filter
Switching out the filter on your furnace or AC is an easy process. Here is a step-by-step breakdown of how to remove a dirty air filter and exchange it for a new one:
- Turn off your furnace: Be sure to shut off your furnace before starting the process.
- Look for 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 clean filter to point in the same direction.
- Slide out the old filter: Be diligent not to knock out any dust or particles.
- Record the date: Write down the date of replacement on the new filter's frame. This will help you keep track of when it's time for you to change it again.
- 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 nicely and close any latches or clips that hold it in the unit.
- Turn on your furnace: Once the clean filter is safely installed, you can turn your furnace back on.
Will a Dirty Air Filter Cause Problems for a Furnace?
The short answer is, yes, a dirty air filter can cause a furnace to cease working or decrease its lifespan. Changing your furnace or air conditioner filter is one of the best things you can do to keep your system operating correctly.