Choosing the proper furnace filter and changing it when it is 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 clogged furnace filter loses its effectiveness, enabling 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 suitable for your needs is not just about keeping your furnace running efficiently. It’s also about creating healthy indoor air quality for your residence.
The health of your family is important to the heating pros at TopTec. We've long focused on bettering indoor air quality in Libertyville. 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?
How Often to Replace the Air Filter in a Furnace
Experts stress it's vital to replace dirty air filters in a furnace or air conditioner routinely. Dirt-clogged filters cause the system to worker harder than it should because it takes extra effort to move air through the plugged-up filter.
Officials suggest inspecting your furnace filter every month and replacing it if it’s dirty. You’ll know if your filter needs changing because it will coated with dirt or dust. People who have pets will probably want 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 commonly found 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 passes 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, inside the furnace. It's usually housed within a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for details regarding filter location of your particular brand and model of furnace.
Is a Furnace Filter the Same as an Air Filter?
The easy answer is, yes. In HVAC, a furnace filter and an air filter or AC filter are effectively the same thing. While people might refer to them differently based on the current season— hot or cold—they are all filters that clean the air in your HVAC system.
They each get rid of dust, allergens, bacteria and other airborne debris 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 Are MERV Ratings and What MERV Rating Do I Need?
Once you find your old furnace filter and decide when it should be replaced, it’s time to pick a replacement. That means deciding on the level of filtration that you need. One way to do that is by picking an appropriate MERV rating for your needs.
MERV is short 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 greater 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 unnecessarily restricting airflow. However, people with certain health conditions may need to purchase a filters with a higher MERV rating.
Where to Insert the Air Filter in a Furnace or Air Conditioning System
Positioning an air filter in a furnace or air conditioner correctly is necessary 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 located on the side of the filter frame. The filter should be placed in the unit with this arrow pointing toward the furnace or air conditioning unit, which is the direction of the airflow. If you're not sure about the airflow direction, it may be helpful to remember that air always moves from the return duct to the heat or cooling source. Therefore, be sure that the arrow points at the furnace or air conditioning unit.
Many people have difficulty remembering which direction to point their air filter. To help remember, consider taking a picture with your mobile 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 perfect time to ask about this is during a scheduled furnace maintenance call.
Changing Your Furnace's 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 located within 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 similarly.
- Slide out the old filter: Be mindful not to knock out any dust or debris.
- Document the date: Write down the date you changed filters on the new filter's frame. This will make it easier to 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 lock it in place.
- Turn on your furnace: Once the clean filter is completely installed, you can turn your furnace back on.
Will a Dirty Air Filter Damage My Furnace?
The shortest answer is, yes, a dirty air filter can cause a furnace to quit working or shorten its lifespan. Changing your furnace or air conditioner filter is one of the simplest things you can do to keep your system working correctly.