Selecting the ideal 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 function in keeping its system operating safely, efficiently and for a long time.
A clogged furnace filter loses its effectiveness, enabling potentially harmful particles to circulate through your home. It also limits airflow, which can damage your furnace and decrease its life span.
Making sure your furnace uses a clean filter that is suitable for your needs is not just about keeping your furnace operating efficiently. It’s also about providing good indoor air quality for your home.
The health of your family is important to the heating and cooling 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 especially tricky question of what direction do you point a filter in your furnace or air conditioner?
When Should I Replace My Furnace Air Filter?
It's important to replace dirty air filters in a furnace or air conditioner routinely. Soiled 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 every 30 days and replacing it if it’s dirty. You’ll know if the filter needs to be changed because it will be gray or black from dirt or dust. Homeowners who have pets that shed will probably have to replace their furnace air filter more often, because a good air filter will trap pet hair circulating in a home.
Locating Your Furnace's Air Filter
In general, a furnace air filter is usually found in the return air duct or blower compartment before the return air gets to the furnace. This makes sure air entering the system is filtered before it goes through the furnace components and is heated.
Depending on the furnace brand, the filter may be positioned on the right, left, bottom or in some cases, inside the furnace. It's generally housed within a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for important information concerning filter location of your particular brand and model of furnace.
Is My Furnace Filter Just a Type of Air Filter?
The easy answer is, yes. In HVAC, a furnace filter and an air filter or air conditioner filter are essentially the same thing. While people may call them 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 Are MERV Ratings and What Rating Is Best for Me?
Once you find your old furnace filter and figure out when it should be substituted for a clean one, it’s time to choose a replacement. That means determining the level of filtration that you need. One approach to this is by selecting 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 the power to filter tinier 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 specific health conditions may need to purchase a filters with a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or Air Conditioner
Installing an air filter in a furnace or air conditioner correctly is necessary for the efficient operation of the unit. 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 at the furnace or air conditioner, which is the direction of the airflow. If you're not sure about the airflow direction, remember that air always moves from the return duct towards the heat or cooling source. Therefore, be sure that the arrow points in the direction of the furnace or AC.
Many people struggle with which direction to point an air filter. To help remember, consider snapping a quick photo 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 be installed. A great time to do this is during a scheduled furnace maintenance visit.
Changing Your Furnace's Air Filter
Replacing the filter on your furnace or air conditioning system is an easy process. Here is a step-by-step rundown of how to take out a dirty air filter and exchange it for a new one:
- Turn off your furnace: Make sure to switch off your furnace before starting up the process.
- Look for the furnace filter: Typically, the filter is located inside 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 new filter to point in the same direction.
- Take out the old filter: Be mindful not to knock out any dust or debris.
- Record the date: Write down the date you replaced the filter on the new filter's frame. This will help your family 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 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 securely and close any latches or clips that secure it in place.
- Turn on your furnace: Once the clean filter is safely 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 cease working or limit its lifespan. Changing your furnace or air conditioner filter is one of the simplest things you can do to keep your system operating effectively.