Selecting 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 critical function in keeping its system operating safely, efficiently and for a long time.
A clogged furnace filter loses its effectiveness, permitting potentially harmful particles to move through your home. It also limits airflow, which can damage your furnace and shorten its life span.
Ensuring your furnace uses a clean filter that is ideal for your needs is not only about keeping your furnace working efficiently. It’s also about delivering good indoor air quality for your household.
Your health is important to the heating and cooling professionals at Rescue Heating & Air. We've long focused on improving indoor air quality in Alice. 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
Experts stress it's important to replace dirty air filters in a furnace or air conditioner periodically. Dirt-clogged filters cause the system to worker harder than it should because it takes more energy to force air through the plugged-up filter.
Officials recommend inspecting your furnace filter every month and replacing it if it’s dirty. You’ll know if your filter needs changing because it will filled with dirt or dust. Those who have pets will probably have 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 located in the return air duct or blower compartment before the return air reaches the furnace. This makes sure air being pulled into the system is filtered before it goes through the furnace components and is heated.
Depending on the type of furnace, the filter may be positioned on the right, left, bottom or in some cases, inside the furnace. It's usually housed within 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 furnace.
Is a Furnace Filter the Same as an Air Filter?
The simple answer is, yes. In HVAC, a furnace filter and an air filter or air conditioning filter are effectively the same thing. While people may call them different things based on the current season— warm or chilly months—they are all filters that clean the air in your residence.
They each remove dust, allergens, bacteria and other particulates from the air that is drawn into the furnace and air conditioning system, ensuring the air circulating throughout your home is clean and safe.
What Is a MERV Rating and What MERV Rating Do I Need?
Once you track down your old furnace filter and determine when it should be changed, it’s time to select a replacement. That means deciding on 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 measures the effectiveness of air filters at trapping airborne particles. 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 an ideal balance between having good indoor air quality without needlessly restricting airflow. However, people with specific health conditions could need a 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 correctly is crucial for the efficient operation of the unit. 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 put in with this arrow pointing in the direction of 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 to the heat or cooling source. Therefore, be sure that the arrow points at the furnace or air conditioner.
Many people have difficulty remembering which direction to install their air filter. To help remember, consider taking a picture with your cell phone after the filter has been properly 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 perfect time to do this is during a routine furnace maintenance visit.
How to Change a Furnace Air Filter
Switching out the filter on your furnace or air conditioning system is a simple process. Here is a step-by-step breakdown of how to retreive a dirty air filter and swap it for a new one:
- 1. Turn off your furnace: Be sure to shut off your furnace before beginning the process.
- Find the furnace filter: Typically, the filter is located within the furnace or in the air return vent. Take note of which direction the arrow points on the filter, because you’ll want the arrow on the new filter to point similarly.
- Take out the old filter: Be mindful not to knock out any dust or debris.
- Note the date: Write down the date you replaced the filter on the new filter's frame. This will help your family 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 nicely and close any latches or clips that secure it in the compartment.
- Turn on your furnace: Once the clean filter is completely installed, 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 quit working or limit its lifespan. Changing your furnace or AC filter is one of the simplest things you can do to keep your system working effectively.