Choosing the right 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 crucial part in keeping its system operating safely, efficiently and for a long time.
A dirty furnace filter loses its effectiveness, enabling potentially harmful particles to flow through your home. It also restricts airflow, which can damage your furnace and reduce its life span.
Making sure your furnace uses a clean filter that is appropriate for your needs is not just about keeping your furnace running efficiently. It’s also about providing excellent indoor air quality for your residence.
The quality of the air your family breathes is important to the HVAC pros at Pure Comfort Heating and Air Conditioning. We've long focused on improving indoor air quality in Streamwood. 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 to Replace the Air Filter in Your Furnace
It is vital to replace dirty air filters in a furnace or air conditioner routinely. Dirty filters cause the system to worker harder than it should because it takes extra effort to force air through the plugged-up filter.
Officials suggest examining your furnace filter monthly 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. Those who have pets will probably 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 commonly found in the return air duct or blower compartment before the return air gets to the furnace. This is so air flowing 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 located on the right, left, bottom or in some cases, inside 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 information concerning filter location of the furnace in your home.
Is a Furnace Filter the Same as an Air Filter?
The simple answer is, yes. In HVAC, a furnace filter and an air filter or air conditioner filter are effectively the same thing. While they might be called different things based on the current season— warm or chilly months—they are all filters that clean the air in your residence.
They each get rid of dust, allergens, bacteria and other contaminants from the air that is drawn into the furnace and air conditioning system, making sure the air circulating throughout 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 determine when it should be changed, 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 higher numbers indicating the power to filter tinier particles.
Experts say a filter with a MERV rating between 8 and 13 offers an appropriate balance between having good indoor air quality without overly restricting airflow. However, people with specific health conditions may need to use a filter with a higher MERV rating.
How to Place the Air Filter in a Furnace or Air Conditioning System
Installing an air filter in a furnace or air conditioner the proper way is important for the efficient operation of the unit. Air filters have a specific 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 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, 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 AC.
Many people struggle with which direction to face their system's air filter. To help remember, consider taking a quick picture with your cellular 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 go. A handy time to do this is during a scheduled furnace maintenance visit.
How to Replace Your Furnace Air Filter
Switching out the filter on your furnace or AC is a quick and easy process. Here is a step-by-step rundown of how to remove a dirty air filter and replace it with a new one:
- Turn off your furnace: Be sure to shut off your furnace before starting up the process.
- Find the furnace filter: Typically, the filter is positioned inside 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.
- Remove the old filter: Be mindful not to knock out any dust or dirt.
- Record the date: Write down the date you replaced the filter on the new filter's frame. This will make it easier to keep track of when it's time for another replacement.
- Insert new filter: Put in the new filter with the arrow pointing toward 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 correctly and close any latches or clips that lock it in the unit.
- Turn on your furnace: Once the new filter is properly installed, you can turn your furnace back on.
Can a Dirty Air Filter Cause a Furnace Not to Work?
The simple 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 easiest things you can do to keep your system operating correctly.