Selecting 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 running safely, efficiently and for a long time.
A clogged furnace filter loses its effectiveness, allowing potentially harmful particles to circulate through your home. It also restricts airflow, which can damage your furnace and decrease its life span.
Making sure your furnace uses a clean filter that is suitable for your needs is not only about keeping your furnace operating efficiently. It’s also about creating good indoor air quality for your household.
Your health is important to the HVAC pros at May's Heating & Air. We've long been dedicated to bettering indoor air quality in Frederick. 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
It is vital to replace dirty air filters in a furnace or air conditioner regularly. Dirty filters cause the system to worker harder than it should because it takes more energy to pull air through the plugged-up filter.
Officials suggest checking your furnace filter monthly and replacing it if it’s dirty. You’ll know if it is dirty because it will filled with dirt or dust. People who have dogs and cats will very 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 commonly found in the return air duct or blower compartment before the return air gets to the furnace. This makes sure air flowing 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 located on the right, left, bottom or in some cases, on the inside of the furnace. It's generally housed within a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for details regarding filter location of your particular brand and model of furnace.
Is a Furnace Filter the Same as an Air Filter?
The easy answer is, yes. In HVAC, a furnace filter and an air filter or AC filter are effectively identical. While they might be called different things based on the current season— summer or winter—they are all filters that clean the air in your residence.
They each get rid of dust, allergens, bacteria and other particulates from the air that is drawn into the furnace and air conditioning system, making sure the air flowing through your home is clean and safe.
What Is a MERV Rating and What MERV Rating Do I Need?
Once you track down your old furnace filter and figure out when it should be substituted for a clean one, it’s time to select a replacement. That means picking 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 contaminants. 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 ideal balance between having healthy indoor air quality without needlessly restricting airflow. However, people with specific health conditions could 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 correctly is crucial for the efficient operation of the heating or cooling system. Air filters are supposed to face a specific direction, indicated by an arrow written on the side of the filter frame. The filter should be installed with this arrow pointing at 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 and then to the heat or cooling source. Therefore, be sure that the arrow points toward the furnace or air conditioner.
Many people are confused by which direction to point their system's air filter. To help remember, consider snapping a quick photo with your cell 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 go. A perfect time to do this is during a regular furnace maintenance appointment.
How to Change a Furnace Air Filter
Changing the filter on your furnace or air conditioner is a quick and easy 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: Make a point to switch off your furnace before beginning the process.
- Locate the furnace filter: Typically, the filter is found within 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 the same way.
- 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 your family keep track of when it's time for the next change.
- 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 your last filter.
- Secure the filter: Make sure the new filter fits nicely and close any latches or clips that hold it in the unit.
- Turn on your furnace: Once the clean filter is properly in place, 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 cease working or shorten its lifespan. Changing your furnace or air conditioner filter is one of the simplest things you can do to keep your system working correctly.