Choosing the correct 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 crucial role in keeping its system running safely, efficiently and for a long time.
An overused furnace filter loses its effectiveness, allowing potentially harmful particles to move through your home. It also slows airflow, which can damage your furnace and decrease its life span.
Making certain your furnace uses a clean filter that is appropriate for your needs is not only about keeping your furnace working efficiently. It’s also about providing good indoor air quality for your household.
The quality of the air your family breathes is important to the HVAC specialists at Point Heating & Cooling. We've long focused on improving indoor air quality in Plover. 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?
How Often to Replace the Air Filter in a Furnace
Experts stress it's critical 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 more energy to move air through the plugged-up filter.
Officials advise examining your furnace filter every month 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 dogs and cats will likely need to replace their furnace air filter more often, because an effective 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 normally installed in the return air duct or blower compartment before the return air gets to the furnace. This is so air entering the system is filtered before it passes through the furnace components and is heated.
Depending on the furnace model, the filter may be positioned on the right, left, bottom or in some cases, inside the furnace. It's generally housed in a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for details concerning filter location of the furnace in your home.
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 AC filter are effectively the same thing. While they might be called different things based on the current season— hot or cold—they are all filters that clean the air in your home.
They each eliminate dust, allergens, bacteria and other contaminants from the air that is drawn into the furnace and air conditioning system, ensuring the air distributed throughout your home is clean and safe.
What Is a MERV Rating and What MERV Rating Do I Need?
Once you locate your old furnace filter and determine when it should be replaced, it’s time to choose 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 is an abbreviation for Minimum Efficiency Reporting Values. The MERV rating calculates the effectiveness of air filters at trapping airborne molecules. The rating scale ranges from 1 to 20, with higher numbers indicating a greater ability to filter smaller particles.
Experts say a filter with a MERV rating between 8 and 13 offers a good balance between having good indoor air quality without unnecessarily restricting airflow. However, people with specific health conditions might need to purchase a filters with a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or Air Conditioner
Putting an air filter in a furnace or air conditioner the proper way is important for the efficient operation of the heating or cooling system. Air filters have a particular 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 toward the furnace or AC, which is the direction of the airflow. If you're unsure about the airflow direction, remember that air always moves from the return duct to the heat or cooling source. Therefore, make certain the arrow points at the furnace or air conditioner.
Many people struggle with which direction to face their system's 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 be installed. A handy time to do this is during a routine furnace maintenance visit.
How to Change a Furnace Air Filter
Changing the filter on your furnace or AC is a simple process. Here is a step-by-step list of how to take out a dirty air filter and replace it with a new one:
- 1. Turn off your furnace: Be sure to turn off your furnace before beginning the process.
- Locate the furnace filter: Typically, the filter is positioned in 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 clean filter to point similarly.
- Slide out the old filter: Be mindful not to knock out any dust or debris.
- Note the date: Write down the date of replacement on the new filter's frame. This will make it easier to 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 your last filter.
- 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 new filter is completely installed, you can turn your furnace back on.
Will a Dirty Air Filter Cause a Furnace Not to Work?
The shortest answer is, yes, a dirty air filter can cause a furnace to stop working or shorten its lifespan. Changing your furnace or AC filter is one of the easiest things you can do to keep your system operating effectively.