Picking out 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 function in keeping its system working safely, efficiently and for a long time.
A clogged furnace filter loses its effectiveness, allowing potentially harmful particles to flow through your home. It also slows airflow, which can damage your furnace and reduce its life span.
Ensuring 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 providing healthy indoor air quality for your household.
The health of your family is important to the heating and cooling professionals at GV Heating & Air. We've long worked with an eye on improving indoor air quality in Crystal and Twin Cities. 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?
When Should I Replace My Furnace Air Filter?
Experts stress it's vital to replace dirty air filters in a furnace or air conditioner routinely. 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 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 pets that shed will probably 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 reaches the furnace. This is so air entering the system is filtered before it goes through the furnace components and is heated.
Depending on the furnace model, the filter may be located 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 about filter location of your 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 essentially identical. 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 residence.
They each eliminate dust, allergens, bacteria and other airborne debris 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 the MERV Rating System and What MERV Rating Should I Have?
Once you find your old furnace filter and figure out when it should be replaced, it’s time to pick a replacement. That means determining the level of filtration that you need. One method to do this is by picking 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 contaminants. The rating scale ranges from 1 to 20, with higher numbers indicating enhanced capabilities to filter small particles.
Experts say a filter with a MERV rating between 8 and 13 offers a good balance between having good indoor air quality without overly restricting airflow. However, people with certain health conditions may need a a higher MERV rating.
Where to Insert the Air Filter in a Furnace or AC Unit
Installing an air filter in a furnace or air conditioner the proper way 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 printed on the side of the filter frame. The filter should be installed with this arrow pointing at the furnace or air conditioning unit, which is the direction of the airflow. If you're doubtful about the airflow direction, try to remember that air always moves from the return duct towards the heat or cooling source. Therefore, make certain the arrow points in the direction of the furnace or air conditioner.
Many people struggle with which direction to install an 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 perfect time to do this is during a scheduled furnace maintenance appointment.
How to Replace Your Furnace Air Filter
Replacing the filter on your furnace or air conditioning system is a quick and easy process. Here is a step-by-step rundown of how to remove a dirty air filter and exchange it for a new one:
- Turn off your furnace: Be sure to switch 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 a mental note or write down which direction the arrow points on the filter, because you’ll want the arrow on the clean filter to point in the same direction.
- Slide out the old filter: Be diligent not to knock out any dust or particles.
- Document 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 the next change.
- 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 your last filter.
- Secure the filter: Make sure the new filter fits nicely and close any latches or clips that lock it in place.
- Turn on your furnace: Once the new filter is properly in place, you can turn your furnace back on.
Can a Dirty Air Filter Damage My Furnace?
The shortest answer is, yes, a dirty air filter can cause a furnace to quit working or reduce its lifespan. Changing your furnace or air conditioning filter is one of the best things you can do to keep your system working efficiently.
