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 vital role in keeping its system working 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 slows airflow, which can damage your furnace and shorten its life span.
Making sure your furnace uses a clean filter that is appropriate for your needs is not just about keeping your furnace working efficiently. It’s also about creating healthy indoor air quality for your home.
Your health is important to the heating and cooling specialists at Stanford Heating & Cooling. We've long focused on bettering indoor air quality in Bloomfield. 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?
When to Replace the Air Filter in Your Furnace
It is 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 work to force air through the plugged-up filter.
Officials suggest inspecting your furnace filter monthly and replacing it if it’s dirty. You’ll know if your filter needs changing because it will coated with dirt or dust. People who have dogs and cats will probably want 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 normally 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 goes through the furnace components and is heated.
Depending on the type of furnace, the filter may be found on the right, left, bottom or in some cases, within the furnace. It's typically housed within a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for facts regarding 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 conditioner filter are effectively the same. While people might refer to them differently based on the current season— summer or winter—they are all filters that clean the air in your home.
They each get rid of dust, allergens, bacteria and other airborne debris from the air that is drawn into the furnace and air conditioning system, making certain the air flowing through 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 figure out when it should be changed, it’s time to pick a replacement. That means deciding on the level of filtration that you need. One method to do this is by choosing an appropriate MERV rating for your needs.
MERV stands for Minimum Efficiency Reporting Values. The MERV rating calculates the effectiveness of air filters at trapping airborne particles. The rating scale ranges from 1 to 20, with greater numbers indicating the power to filter small particles.
Experts say a filter with a MERV rating between 8 and 13 offers an appropriate balance between having good indoor air quality without unnecessarily restricting airflow. However, people with certain health conditions could need to purchase a filters with a higher MERV rating.
Where to Insert the Air Filter in a Furnace or Air Conditioner
Positioning an air filter in a furnace or air conditioner correctly is necessary for the efficient operation of the heating or cooling system. Air filters are designed to be installed in a particular direction, indicated by an arrow located on the side of the filter frame. The filter should be installed with this arrow pointing in the direction of the furnace or AC, which is the direction of the airflow. If you're not sure about the airflow direction, it may be helpful to remember that air always moves from the return duct towards the heat or cooling source. Therefore, be sure that the arrow points at the furnace or air conditioner.
Many people have difficulty remembering which direction to install an air filter. To help remember, consider taking a picture with your cellular phone after the filter has been properly 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 go. A great time to do this is during a routine furnace maintenance call.
How to Change a Furnace Air Filter
Switching out the filter on your furnace or air conditioner is a quick and easy process. Here is a step-by-step rundown of how to remove a dirty air filter and swap it for a new one:
- Turn off your furnace: Make sure to shut off your furnace before starting up the process.
- Find the furnace filter: Typically, the filter is located 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 clean filter to point the same way.
- Take out the old filter: Be mindful not to knock out any dust or dirt.
- Document the date: Write down the date of replacement 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 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 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 stop working or reduce its lifespan. Changing your furnace or air conditioner filter is one of the best things you can do to keep your system operating effectively.
