Picking out the right furnace filter and changing it when it becomes dirty is as important to your HVAC system as changing the oil is to your car. Each plays a crucial part in keeping its system operating safely, efficiently and for a long time.
A clogged furnace filter loses its effectiveness, enabling potentially harmful particles to flow through your home. It also limits 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 operating efficiently. It’s also about delivering healthy indoor air quality for your home.
Your health is important to the heating and cooling pros at Forster Heating. We've long worked with an eye on bettering indoor air quality in Auburn. 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?
It is critical to replace dirty air filters in a furnace or air conditioner routinely. Dirt-clogged filters cause the system to worker harder than it should because it takes extra effort to move air through the plugged-up filter.
Officials recommend examining your furnace filter every 30 days and replacing it if it’s dirty. You’ll know if your filter needs changing because it will be gray or black from dirt or dust. Homeowners who have pets will very likely need 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 found in the return air duct or blower compartment before the return air reaches the furnace. This is so air flowing into the system is filtered before it passes 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, on the inside of the furnace. It's generally housed within a slot, frame or cabinet for simple access and replacement. Always refer to your furnace's owner manual for details regarding filter location of the furnace in your home.
Is My Furnace Filter Just a Type of Air Filter?
The straightforward answer is, yes. In HVAC, a furnace filter and an air filter or air conditioning filter are basically the same. While they might be called different things based on the current season— warm or chilly months—they are all filters that clean the air in your HVAC system.
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 sure the air distributed throughout your home is clean and safe.
What Are MERV Ratings and What MERV Rating Do I Need?
Once you locate your old furnace filter and decide when it should be substituted for a clean one, it’s time to choose a replacement. That means determining the level of filtration that you need. One way to do that is by selecting an appropriate MERV rating for your needs.
MERV stands for Minimum Efficiency Reporting Values. The MERV rating indicates the effectiveness of air filters at trapping airborne contaminants. The rating scale ranges from 1 to 20, with bigger numbers indicating enhanced capabilities to filter smaller particles.
Experts say a filter with a MERV rating between 8 and 13 offers an ideal balance between having healthy 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 AC Unit
Positioning an air filter in a furnace or air conditioner the proper way is crucial for the efficient operation of the system. Air filters are supposed to face a certain direction, indicated by an arrow printed on the side of the filter frame. The filter should be installed with this arrow pointing in the direction of the furnace or air conditioning unit, 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 to the heat or cooling source. Therefore, make certain the arrow points toward the furnace or air conditioner.
Many people struggle with which direction to face their air filter. To help remember, consider snapping a quick photo 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 be installed. A handy time to do this is during a routine furnace maintenance call.
Changing Your Furnace's 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 exchange it for a new one:
- Turn off your furnace: Make a point to switch off your furnace before starting the process.
- Look for the furnace filter: Typically, the filter is positioned 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 new filter to point the same way.
- Remove the old filter: Be diligent not to knock out any dust or debris.
- Record the date: Write down the date you replaced the filter on the new filter's frame. This will make it easier to 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 at 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 hold it in place.
- Turn on your furnace: Once the new filter is completely in place, 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 quit 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 correctly.
