Choosing the right 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 crucial role in keeping its system operating safely, efficiently and for a long time.
A dirty furnace filter loses its effectiveness, allowing potentially harmful particles to circulate through your home. It also slows airflow, which can damage your furnace and reduce its life span.
Ensuring your furnace uses a clean filter that is appropriate for your needs is not only about keeping your furnace working efficiently. It’s also about providing good indoor air quality for your residence.
The health of your family is important to the HVAC professionals at Olde Towne Heating & Air. We've long worked with an eye on improving indoor air quality in Mount Pleasant. 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?
How Often to Replace the Air Filter in a Furnace
It's important to replace dirty air filters in a furnace or air conditioner periodically. Soiled filters cause the system to worker harder than it should because it takes more energy to move air through the plugged-up filter.
Officials suggest checking your furnace filter monthly and replacing it if it’s dirty. You’ll know if it is dirty because it will filled with dirt or dust. Those who have pets that shed 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.
How to Find the Furnace's Air Filter
In general, a furnace air filter is usually located in the return air duct or blower compartment before the return air reaches 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 furnace brand, the filter may be found on the right, left, bottom or in some cases, within the furnace. It's usually housed inside of a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for facts about filter location of your 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 air conditioning filter are effectively the same thing. 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 home.
They each get rid of dust, allergens, bacteria and other contaminants 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 determine when it should be substituted for a clean one, it’s time to pick a replacement. That means determining the level of filtration that you need. One way to do that 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 greater numbers indicating enhanced capabilities 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 certain health conditions may need to use a filter with a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or AC Unit
Putting an air filter in a furnace or air conditioner correctly is crucial for the efficient operation of the system. Air filters are designed to be installed in a specific direction, indicated by an arrow printed on the side of the filter frame. The filter should be put in with this arrow pointing at the furnace or air conditioning unit, which is the direction of the airflow. If you're doubtful about the airflow direction, it may be helpful to remember that air always moves from the return duct and then to the heat or cooling source. Therefore, make certain the arrow points at the furnace or AC.
Many people struggle with which direction to face an 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 point. A handy time to ask about this is during a regular furnace maintenance appointment.
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 retreive 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 up the process.
- Locate the furnace filter: Typically, the filter is found in 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 similarly.
- Take out the old filter: Be careful not to knock out any dust or dirt.
- Note the date: Write down the date you replaced the filter on the new filter's frame. This will help you 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 your last filter.
- Secure the filter: Make sure the new filter fits correctly and close any latches or clips that hold it in the unit.
- Turn on your furnace: Once the clean filter is properly in place, you can turn your furnace back on.
Will 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 decrease its lifespan. Changing your furnace or air conditioner filter is one of the best things you can do to keep your system operating efficiently.