Choosing the ideal 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 critical role in keeping its system running safely, efficiently and for a long time.
A clogged furnace filter loses its effectiveness, enabling potentially harmful particles to move through your home. It also limits airflow, which can damage your furnace and decrease its life span.
Ensuring your furnace uses a clean filter that is appropriate for your needs is not merely about keeping your furnace operating efficiently. It’s also about creating good indoor air quality for your home.
Your health is important to the heating and cooling professionals at Rapids Sheet Metal Works Inc. We've long worked with an eye on bettering indoor air quality in Wisconsin Rapids. Here, we’ve answered common questions about HVAC filters, including that very 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's vital to replace dirty air filters in a furnace or air conditioner periodically. Soiled filters cause the system to worker harder than it should because it takes extra work to force air through the plugged-up filter.
Officials recommend inspecting your furnace filter monthly and replacing it if it’s dirty. You’ll know if your filter needs changing because it will filled with dirt or dust. People who have dogs and cats will probably want 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 normally located in the return air duct or blower compartment before the return air goes back into the furnace. This ensures air flowing into the system is filtered before it moves 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, within the furnace. It's usually housed inside of a slot, frame or cabinet for easy 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 simple answer is, yes. In HVAC, a furnace filter and an air filter or air conditioner filter are basically the same. While people might refer to them differently based on the current season— warm or chilly months—they are all filters that clean the air in your HVAC system.
They each eliminate 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 the MERV Rating System and What MERV Rating Should I Have?
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 deciding on the level of filtration that you need. One way to do that is by selecting 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 bigger numbers indicating enhanced capabilities to filter tinier particles.
Experts say a filter with a MERV rating between 8 and 13 offers an ideal balance between having adequate indoor air quality without needlessly restricting airflow. However, people with some health conditions might need to purchase a filters with a higher MERV rating.
How to Place the Air Filter in a Furnace or AC Unit
Installing an air filter in a furnace or air conditioner properly is necessary for the efficient operation of the heating or cooling system. 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 installed with this arrow pointing in the direction of the furnace or AC, which is the direction of the airflow. If you're not sure 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 sure the arrow points in the direction of the furnace or air conditioning unit.
Many people are confused by which direction to point their air filter. To help remember, consider taking a quick picture 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 be installed. A handy time to ask about this is during a regular furnace maintenance appointment.
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 turn off your furnace before starting the process.
- Look for the furnace filter: Typically, the filter is found within 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 replacement filter to point the same way.
- Take out the old filter: Be mindful not to knock out any dust or particles.
- Note the date: Write down the date of replacement on the new filter's frame. This will help you keep track of when it's time for you to change it again.
- Insert 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 securely and close any latches or clips that secure it in the compartment.
- Turn on your furnace: Once the new filter is completely installed, you can turn your furnace back on.
Can a Dirty Air Filter Cause a Furnace Not to Work?
The shortest answer is, yes, a dirty air filter can cause a furnace to stop working or limit its lifespan. Changing your furnace or AC filter is one of the easiest things you can do to keep your system running correctly.