Selecting the right 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 crucial role in keeping its system operating safely, efficiently and for a long time.
A clogged furnace filter loses its effectiveness, enabling potentially harmful particles to circulate through your home. It also restricts airflow, which can damage your furnace and shorten its life span.
Making sure your furnace uses a clean filter that is ideal for your needs is not merely about keeping your furnace operating efficiently. It’s also about delivering good indoor air quality for your household.
The health of your family is important to the HVAC pros at Stieferman Heating Company Inc. We've long focused on enhancing indoor air quality in Jefferson 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 to Replace the Air Filter in Your Furnace
Experts stress it's important 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 force air through the plugged-up filter.
Officials advise examining your furnace filter every 30 days and replacing it if it’s dirty. You’ll know if the filter needs to be changed because it will filled with dirt or dust. Those who have pets 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 normally located 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 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, within the furnace. It's usually housed in a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for information about filter location of your particular brand and model of furnace.
Are Air Filters and Furnace Filters the Same Thing?
The easy answer is, yes. In HVAC, a furnace filter and an air filter or air conditioning filter are effectively the same. While people might refer to them differently based on the current season— hot or cold—they are all filters that clean the air in your HVAC system.
They each eliminate dust, allergens, bacteria and other contaminants 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 Are MERV Ratings and What MERV Rating Do I Need?
Once you locate your old furnace filter and decide when it should be replaced, it’s time to choose a replacement. That means deciding on the level of filtration that you need. One way to do that is by choosing 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 molecules. The rating scale ranges from 1 to 20, with bigger numbers indicating a greater ability to filter smaller particles.
Experts say a filter with a MERV rating between 8 and 13 offers an ideal balance between having good indoor air quality without needlessly restricting airflow. However, people with specific health conditions may need to purchase a filters with a higher MERV rating.
Where to Insert the Air Filter in a Furnace or Air Conditioner
Putting an air filter in a furnace or air conditioner properly is important for the efficient operation of the unit. Air filters are designed to be installed in a certain direction, indicated by an arrow printed on the side of the filter frame. The filter should be put in with this arrow pointing at the furnace or AC, which is the direction of the airflow. If you're unsure about the airflow direction, try to remember that air always moves from the return duct and then 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 point their system's air filter. To help remember, consider taking a quick 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 go. A handy time to inquire about this is during a regular furnace maintenance visit.
How to Replace Your Furnace Air Filter
Switching out the filter on your furnace or air conditioner is a simple process. Here is a step-by-step list of how to take out a dirty air filter and swap it for a new one:
- Turn off your furnace: Make a point to shut off your furnace before starting up the process.
- Find the furnace filter: Typically, the filter is positioned inside the furnace or in the air return vent. Make a mental note or write down which direction the arrow points on the filter, because you’ll want the arrow on the new filter to point similarly.
- Remove the old filter: Be diligent not to knock out any dust or particles.
- Record the date: Write down the date you changed filters on the new filter's frame. This will make it easier to keep track of when it's time for another replacement.
- 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 correctly and close any latches or clips that lock it in place.
- Turn on your furnace: Once the clean filter is safely secured, you can turn your furnace back on.
Will a Dirty Air Filter Damage My Furnace?
The simple answer is, yes, a dirty air filter can cause a furnace to cease working or decrease its lifespan. Changing your furnace or AC filter is one of the easiest things you can do to keep your system running effectively.