Selecting 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 vital part in keeping its system running safely, efficiently and for a long time.
A dirty furnace filter loses its effectiveness, permitting potentially harmful particles to circulate through your home. It also slows airflow, which can damage your furnace and shorten its life span.
Making certain your furnace uses a clean filter that is ideal for your needs is not only about keeping your furnace running efficiently. It’s also about delivering good indoor air quality for your residence.
The health of your family is important to the heating and cooling specialists at Bishop Heating & Air Conditioning. We've long been dedicated to bettering indoor air quality in Bishop. Here, we’ve answered common 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
It is critical 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 extra effort to pull air through the plugged-up filter.
Officials suggest inspecting 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. Homeowners who have pets that shed 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 commonly found in the return air duct or blower compartment before the return air goes back into the furnace. This makes sure 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 generally housed in a slot, frame or cabinet for easy access and replacement. Always refer to your furnace's owner manual for information regarding 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 air conditioner 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 home.
They each remove dust, allergens, bacteria and other contaminants 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 a MERV Rating and What Rating Is Best for Me?
Once you locate your old furnace filter and decide when it should be replaced, it’s time to select 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 indicates the effectiveness of air filters at trapping airborne molecules. The rating scale ranges from 1 to 20, with higher numbers indicating enhanced capabilities 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 unnecessarily restricting airflow. However, people with some health conditions might need a a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or AC Unit
Installing an air filter in a furnace or air conditioner the proper way is necessary for the efficient operation of the system. Air filters are supposed to face 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 at the furnace or air conditioning unit, 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 certain the arrow points in the direction of the furnace or air conditioning unit.
Many people are confused by which direction to face their air filter. To help remember, consider taking a 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 be installed. A handy time to do this is during a regular furnace maintenance call.
How to Replace Your Furnace Air Filter
Replacing the filter on your furnace or air conditioning system is a simple process. Here is a step-by-step breakdown of how to remove a dirty air filter and swap it for a new one:
- Turn off your furnace: Make sure to switch off your furnace before starting the process.
- Look for the furnace filter: Typically, the filter is positioned 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 new filter to point the same way.
- Remove the old filter: Be mindful 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 help you keep track of when it's time for you to change it again.
- Slide in new filter: Put in the new filter with the arrow pointing toward 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 securely and close any latches or clips that hold it in place.
- Turn on your furnace: Once the new filter is safely secured, you can turn your furnace back on.
Will a Dirty Air Filter Cause a Furnace Not to Work?
The short answer is, yes, a dirty air filter can cause a furnace to cease working or limit its lifespan. Changing your furnace or air conditioning filter is one of the easiest things you can do to keep your system operating effectively.