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 role in keeping its system running safely, efficiently and for a long time.
A clogged furnace filter loses its effectiveness, permitting potentially harmful particles to circulate through your home. It also restricts 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 just about keeping your furnace operating efficiently. It’s also about delivering good indoor air quality for your residence.
The quality of the air your family breathes is important to the heating and cooling professionals at Tru Air Systems LLC. We've long worked with an eye on improving indoor air quality in Albuquerque. Here, we’ve answered frequent questions about HVAC filters, including that very tricky question of what direction do you point a filter in your furnace or air conditioner?
How Often to Replace the Air Filter in a Furnace
It is important to replace dirty air filters in a furnace or air conditioner regularly. Soiled filters cause the system to worker harder than it should because it takes extra work to pull air through the plugged-up filter.
Officials recommend checking your furnace filter every 30 days and replacing it if it’s dirty. You’ll know if it is dirty because it will be gray or black from dirt or dust. People who have pets 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 usually located in the return air duct or blower compartment before the return air reaches the furnace. This makes sure air flowing into the system is filtered before it goes through the furnace components and is heated.
Depending on the furnace model, the filter may be found on the right, left, bottom or in some cases, inside 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 information about filter location of the furnace in your home.
Is a Furnace Filter the Same as an 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— hot or cold—they are all filters that clean the air in your residence.
They each eliminate dust, allergens, bacteria and other contaminants from the air that is drawn into the furnace and air conditioning system, ensuring the air distributed throughout your home is clean and safe.
What Is a MERV Rating and What MERV Rating Do I Need?
Once you locate your old furnace filter and figure out when it should be replaced, it’s time to select a replacement. That means determining the level of filtration that you need. One approach to this is by picking an appropriate MERV rating for your needs.
MERV stands for Minimum Efficiency Reporting Values. The MERV rating calculates the effectiveness of air filters at trapping airborne particles. The rating scale ranges from 1 to 20, with higher numbers indicating a greater ability to filter smaller particles.
Experts say a filter with a MERV rating between 8 and 13 offers an appropriate balance between having adequate indoor air quality without needlessly restricting airflow. However, people with certain health conditions might need to use a filter with a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or Air Conditioner
Positioning an air filter in a furnace or air conditioner properly is important for the efficient operation of the unit. Air filters are supposed to face a specific direction, indicated by an arrow written on the side of the filter frame. The filter should be placed in the unit with this arrow pointing at the furnace or air conditioner, 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, be sure that the arrow points in the direction of the furnace or AC.
Many people struggle with which direction to install an air filter. To help remember, consider taking a picture with your mobile 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 routine furnace maintenance visit.
How to Change a Furnace Air Filter
Replacing the filter on your furnace or AC is an easy process. Here is a step-by-step rundown of how to retreive a dirty air filter and swap it for a new one:
- 1. Turn off your furnace: Make a point to switch off your furnace before starting up the process.
- Find the furnace filter: Typically, the filter is found 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 replacement filter to point in the same direction.
- Remove the old filter: Be careful 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 another replacement.
- Slide 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 your last filter.
- Secure the filter: Make sure the new filter fits securely and close any latches or clips that secure it in place.
- Turn on your furnace: Once the replacement filter is safely secured, you can turn your furnace back on.
Will a Dirty Air Filter Cause a Furnace Not to Work?
The shortest answer is, yes, a dirty air filter can cause a furnace to quit working or decrease its lifespan. Changing your furnace or AC filter is one of the simplest things you can do to keep your system working correctly.