Selecting 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 critical function in keeping its system running safely, efficiently and for a long time.
A dirty furnace filter loses its effectiveness, permitting 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 suitable for your needs is not just 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 HVAC specialists at Aggressive Mechanical. We've long focused on bettering indoor air quality in Neptune City. Here, we’ve answered frequent questions about HVAC filters, including that especially 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 regularly. Soiled filters cause the system to worker harder than it should because it takes extra effort to pull air through the plugged-up filter.
Officials advise inspecting your furnace filter monthly and replacing it if it’s dirty. You’ll know if the filter needs to be changed because it will coated with dirt or dust. Homeowners who have dogs and cats 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 ensures air flowing into the system is filtered before it goes through the furnace components and is heated.
Depending on the furnace model, the filter may be located on the right, left, bottom or in some cases, within the furnace. It's typically housed inside of a slot, frame or cabinet for simple access and replacement. Always refer to your furnace's owner manual for important information regarding filter location of the furnace in your home.
Is a Furnace Filter the Same as an Air Filter?
The straightforward answer is, yes. In HVAC, a furnace filter and an air filter or AC filter are effectively identical. While they might be called different things based on the current season— summer or winter—they are all filters that clean the air in your HVAC system.
They each remove 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 Is the MERV Rating System and What MERV Rating Do I Need?
Once you locate your old furnace filter and figure out when it should be changed, it’s time to pick a replacement. That means picking the level of filtration that you need. One method to do this is by selecting an appropriate MERV rating for your needs.
MERV is an abbreviation for Minimum Efficiency Reporting Values. The MERV rating measures the effectiveness of air filters at trapping airborne particles. The rating scale ranges from 1 to 20, with bigger numbers indicating enhanced capabilities to filter tinier particles.
Experts say a filter with a MERV rating between 8 and 13 offers an ideal balance between having adequate indoor air quality without unnecessarily restricting airflow. However, people with specific health conditions might need a a higher MERV rating.
Where to Insert the Air Filter in a Furnace or Air Conditioner
Installing an air filter in a furnace or air conditioner properly is necessary for the efficient operation of the system. Air filters have a certain direction, indicated by an arrow printed on the side of the filter frame. The filter should be installed 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, try to remember that air always moves from the return duct and then to the heat or cooling source. Therefore, make certain the arrow points toward the furnace or AC.
Many people are confused by which direction to face their air filter. To help remember, consider taking a picture with your cell 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 point. A handy time to do this is during a regular furnace maintenance appointment.
How to Change a Furnace Air Filter
Replacing the filter on your furnace or AC is an easy process. Here is a step-by-step rundown of how to take out a dirty air filter and replace it with a new one:
- Turn off your furnace: Make sure to switch off your furnace before starting the process.
- Find the furnace filter: Typically, the filter is positioned in the furnace or in the air return vent. Take note of which direction the arrow points on the filter, because you’ll want the arrow on the replacement filter to point the same way.
- Remove the old filter: Be careful not to knock out any dust or debris.
- Note 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.
- Put in 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 nicely and close any latches or clips that secure it in the unit.
- Turn on your furnace: Once the replacement filter is completely secured, you can turn your furnace back on.
Can a Dirty Air Filter Cause Problems for a 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 conditioning filter is one of the easiest things you can do to keep your system operating efficiently.