Choosing the proper 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 crucial part in keeping its system working safely, efficiently and for a long time.
A clogged furnace filter loses its effectiveness, allowing potentially harmful particles to circulate 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 ideal for your needs is not only about keeping your furnace operating efficiently. It’s also about creating good indoor air quality for your household.
Your health is important to the heating professionals at Kohles & Bach Heating & Cooling. We've long worked with an eye on enhancing indoor air quality in Des Moines. 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 vital to replace dirty air filters in a furnace or air conditioner regularly. Soiled filters cause the system to worker harder than it should because it takes extra work to pull air through the plugged-up filter.
Officials suggest examining your furnace filter every month and replacing it if it’s dirty. You’ll know if it is dirty because it will coated with dirt or dust. People who have dogs and cats will very likely need to replace their furnace air filter more often, because an effective 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 commonly found in the return air duct or blower compartment before the return air reaches the furnace. This ensures air entering the system is filtered before it moves 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 generally 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.
Are Air Filters and Furnace Filters the Same Thing?
The simple answer is, yes. In HVAC, a furnace filter and an air filter or air conditioning filter are effectively the same. While people might refer to them differently based on the current season— summer or winter—they are all filters that clean the air in your home.
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 the MERV Rating System and What Rating Is Best for Me?
Once you locate your old furnace filter and decide when it should be changed, it’s time to select a replacement. That means determining 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 contaminants. The rating scale ranges from 1 to 20, with higher 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 the proper way is important for the efficient operation of the unit. 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 installed with this arrow pointing toward the furnace or AC, 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 and then to the heat or cooling source. Therefore, be sure that the arrow points toward the furnace or air conditioning unit.
Many people have difficulty remembering 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 ask about this is during a scheduled furnace maintenance call.
How to Replace Your Furnace Air Filter
Switching out the filter on your furnace or air conditioner is an easy process. Here is a step-by-step breakdown of how to remove a dirty air filter and swap 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 positioned 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 new filter to point in the same direction.
- Remove the old filter: Be mindful 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 the next change.
- 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 dirty filter you just removed.
- Secure the filter: Make sure the new filter fits securely and close any latches or clips that lock it in place.
- Turn on your furnace: Once the clean filter is completely secured, 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 effectively.