Picking out the right 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 critical function in keeping its system operating safely, efficiently and for a long time.
An overused furnace filter loses its effectiveness, enabling potentially harmful particles to circulate through your home. It also restricts airflow, which can damage your furnace and shorten its life span.
Ensuring your furnace uses a clean filter that is appropriate for your needs is not only about keeping your furnace running efficiently. It’s also about providing healthy indoor air quality for your home.
The quality of the air your family breathes is important to the heating and cooling pros at Rescue Heating & Air. We've long been dedicated to bettering indoor air quality in Alice. 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 to Replace the Air Filter in Your Furnace
It is important to replace dirty air filters in a furnace or air conditioner periodically. Dirt-clogged 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 every 30 days and replacing it if it’s dirty. You’ll know if your filter needs changing because it will be gray or black from dirt or dust. Homeowners who have dogs and cats will likely want to replace their furnace air filter more often, because a good 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 located in the return air duct or blower compartment before the return air reaches the furnace. This makes sure air being pulled into the system is filtered before it moves through the furnace components and is heated.
Depending on the furnace model, the filter may be found on the right, left, bottom or in some cases, inside the furnace. It's usually housed in a slot, frame or cabinet for easy access and replacement. Always refer to your furnace's owner manual for facts concerning filter location of your particular brand and model of furnace.
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 conditioning filter are basically identical. While people may call them 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 airborne debris from the air that is drawn into the furnace and air conditioning system, making certain the air circulating throughout your home is clean and safe.
What Are MERV Ratings and What MERV Rating Should I Have?
Once you find your old furnace filter and figure out when it should be changed, it’s time to select a replacement. That means determining the level of filtration that you need. One approach to this 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 particles. The rating scale ranges from 1 to 20, with greater 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 some health conditions might need to use a filter with a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or AC Unit
Positioning 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 printed on the side of the filter frame. The filter should be installed with this arrow pointing toward the furnace or AC, 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 to the heat or cooling source. Therefore, be sure that the arrow points in the direction of the furnace or air conditioning unit.
Many people have difficulty remembering which direction to face an air filter. To help remember, consider taking a 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 perfect time to do this is during a regular furnace maintenance appointment.
Changing Your Furnace's Air Filter
Replacing the filter on your furnace or AC 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 sure to switch off your furnace before beginning the process.
- Locate the furnace filter: Typically, the filter is located within 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 replacement filter to point in the same direction.
- Slide out the old filter: Be careful 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 you 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 your last filter.
- Secure the filter: Make sure the new filter fits securely and close any latches or clips that lock it in place.
- Turn on your furnace: Once the replacement filter is properly installed, you can turn your furnace back on.
Will a Dirty Air Filter Cause a Furnace Not to Work?
The short answer is, yes, a dirty air filter can cause a furnace to quit working or decrease its lifespan. Changing your furnace or AC filter is one of the best things you can do to keep your system running correctly.