Choosing the proper 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 critical function in keeping its system running safely, efficiently and for a long time.
An overused furnace filter loses its effectiveness, allowing potentially harmful particles to circulate through your home. It also restricts airflow, which can damage your furnace and shorten its life span.
Making sure your furnace uses a clean filter that is ideal for your needs is not merely about keeping your furnace running efficiently. It’s also about creating good indoor air quality for your residence.
The quality of the air your family breathes is important to the heating specialists at Northwest Services. We've long worked with an eye on enhancing indoor air quality in Toledo. Here, we’ve answered common questions about HVAC filters, including that very 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's critical 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 more energy to force air through the plugged-up filter.
Officials recommend examining 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. Those 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.
Where Is the Air Filter in My Furnace?
In general, a furnace air filter is commonly installed in the return air duct or blower compartment before the return air goes back into the furnace. This is so air being pulled into the system is filtered before it moves through the furnace components and is heated.
Depending on the furnace brand, the filter may be located on the right, left, bottom or in some cases, on the inside of the furnace. It's usually housed inside of a slot, frame or cabinet for simple access and replacement. Always refer to your furnace's owner manual for important information about filter location of your particular brand and model of furnace.
Is My Furnace Filter Just a Type of Air Filter?
The simple answer is, yes. In HVAC, a furnace filter and an air filter or AC filter are essentially 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 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 sure 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 find your old furnace filter and determine 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 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 molecules. 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 an appropriate balance between having healthy indoor air quality without needlessly restricting airflow. However, people with some health conditions may need a a higher MERV rating.
Where to Insert the Air Filter in a Furnace or AC Unit
Positioning an air filter in a furnace or air conditioner the proper way is necessary for the efficient operation of the system. Air filters have a particular direction, indicated by an arrow located on the side of the filter frame. The filter should be put in with this arrow pointing toward the furnace or air conditioner, 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 sure the arrow points in the direction of the furnace or AC.
Many people have difficulty remembering which direction to point their 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 be installed. A perfect time to inquire about this is during a regular furnace maintenance appointment.
How to Change a Furnace Air Filter
Changing the filter on your furnace or air conditioning system is a simple process. Here is a step-by-step breakdown of how to retreive a dirty air filter and replace it with a new one:
- Turn off your furnace: Make a point to shut off your furnace before starting up the process.
- Locate 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 replacement filter to point similarly.
- Take out the old filter: Be careful not to knock out any dust or debris.
- Note the date: Write down the date you changed filters on the new filter's frame. This will help you keep track of when it's time for the next change.
- Slide 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 the old filter you are replacing.
- Secure the filter: Make sure the new filter fits correctly and close any latches or clips that lock it in the compartment.
- Turn on your furnace: Once the replacement filter is completely secured, you can turn your furnace back on.
Can a Dirty Air Filter Damage My Furnace?
The simple answer is, yes, a dirty air filter can cause a furnace to cease working or reduce its lifespan. Changing your furnace or air conditioner filter is one of the easiest things you can do to keep your system running correctly.