Selecting the right 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 working 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 limits 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 merely about keeping your furnace working efficiently. It’s also about delivering healthy indoor air quality for your household.
Your health is important to the heating and cooling pros at Anderson Heating & A/C. We've long focused on improving indoor air quality in Carson City. 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 Should I Replace My Furnace Air Filter?
Experts stress it's critical to replace dirty air filters in a furnace or air conditioner regularly. Dirt-clogged filters cause the system to worker harder than it should because it takes extra effort to pull air through the plugged-up filter.
Officials advise checking your furnace filter every month and replacing it if it’s dirty. You’ll know if the filter needs to be changed because it will be gray or black from dirt or dust. Homeowners who have dogs and cats will very likely need to replace their furnace air filter more often, because a quality 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 gets to the furnace. This ensures air flowing into the system is filtered before it goes 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, 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 facts about filter location of your particular brand and model of furnace.
Is a Furnace Filter the Same as an Air Filter?
The straightforward answer is, yes. In HVAC, a furnace filter and an air filter or AC filter are basically the same. 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 home.
They each eliminate 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 Is the MERV Rating System and What MERV Rating Should I Have?
Once you track down 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 approach to this is by picking 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 particles. The rating scale ranges from 1 to 20, with higher numbers indicating the power to filter smaller particles.
Experts say a filter with a MERV rating between 8 and 13 offers a good balance between having adequate indoor air quality without overly restricting airflow. However, people with specific health conditions could need to use a filter with a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or Air Conditioning System
Putting an air filter in a furnace or air conditioner properly is necessary for the efficient operation of the unit. Air filters are designed to be installed in a particular direction, indicated by an arrow written on the side of the filter frame. The filter should be put in with this arrow pointing toward the furnace or air conditioning unit, which is the direction of the airflow. If you're unsure about the airflow direction, remember that air always moves from the return duct and then to 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 face their system's air filter. To help remember, consider taking a picture with your mobile 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 go. A handy time to ask about this is during a routine furnace maintenance call.
Changing Your Furnace's Air Filter
Switching out the filter on your furnace or air conditioning system is an easy process. Here is a step-by-step rundown of how to take out a dirty air filter and exchange it for a new one:
- Turn off your furnace: Make sure to shut off your furnace before starting the process.
- Look for the furnace filter: Typically, the filter is located inside 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 in the same direction.
- Remove the old filter: Be careful not to knock out any dust or dirt.
- Record 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 in the direction of the furnace, which is the direction of airflow and should be the same direction the arrow pointed on the dirty filter you just removed.
- Secure the filter: Make sure the new filter fits nicely and close any latches or clips that secure it in place.
- Turn on your furnace: Once the clean filter is properly in place, you can turn your furnace back on.
Will a Dirty Air Filter Damage My Furnace?
The short answer is, yes, a dirty air filter can cause a furnace to quit 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 working correctly.