Choosing the correct 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 function in keeping its system working safely, efficiently and for a long time.
A clogged furnace filter loses its effectiveness, allowing potentially harmful particles to move through your home. It also slows airflow, which can damage your furnace and reduce its life span.
Ensuring your furnace uses a clean filter that is ideal for your needs is not only about keeping your furnace working efficiently. It’s also about delivering healthy indoor air quality for your home.
The health of your family is important to the heating and cooling specialists at Northwest Services. We've long focused 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 Should I Replace My Furnace Air Filter?
It is vital to replace dirty air filters in a furnace or air conditioner periodically. Dirty filters cause the system to worker harder than it should because it takes extra work to pull air through the plugged-up filter.
Officials recommend inspecting your furnace filter monthly and replacing it if it’s dirty. You’ll know if it is dirty because it will coated with dirt or dust. Those who have pets that shed will likely want to replace their furnace air filter more often, because a quality 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 reaches 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 positioned on the right, left, bottom or in some cases, on the inside of the furnace. It's typically housed in a slot, frame or cabinet for easy access and replacement. Always refer to your furnace's owner manual for information concerning 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 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 residence.
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 Is a MERV Rating and What Rating Is Best for Me?
Once you find your old furnace filter and decide when it should be changed, it’s time to select a replacement. That means picking the level of filtration that you need. One approach to this is by selecting an appropriate MERV rating for your needs.
MERV is short 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 smaller particles.
Experts say a filter with a MERV rating between 8 and 13 offers a good balance between having healthy indoor air quality without unnecessarily restricting airflow. However, people with specific health conditions might need to purchase a filters with a higher MERV rating.
Where to Insert the Air Filter in a Furnace or AC Unit
Putting 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 supposed to face a certain direction, indicated by an arrow located on the side of the filter frame. The filter should be put in with this arrow pointing in the direction of the furnace or air conditioner, 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, make sure the arrow points at the furnace or air conditioner.
Many people have difficulty remembering which direction to point their system's 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 perfect time to do this is during a scheduled furnace maintenance call.
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 breakdown of how to remove a dirty air filter and replace it with a new one:
- Turn off your furnace: Make a point to turn off your furnace before starting up the process.
- Locate the furnace filter: Typically, the filter is positioned 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 new filter to point in the same direction.
- Remove the old filter: Be diligent not to knock out any dust or particles.
- Document 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 you to change it again.
- Put in new filter: Put in the new filter with the arrow pointing in the direction of 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 nicely and close any latches or clips that lock it in place.
- Turn on your furnace: Once the replacement filter is safely installed, 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 stop working or shorten its lifespan. Changing your furnace or air conditioning filter is one of the best things you can do to keep your system working effectively.