Picking out the ideal 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 role in keeping its system running safely, efficiently and for a long time.
An overused furnace filter loses its effectiveness, allowing potentially harmful particles to circulate through your home. It also slows 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 just about keeping your furnace running efficiently. It’s also about creating healthy indoor air quality for your household.
Your health is important to the heating professionals at Thurston Heating & Air Conditioning. We've long focused on improving indoor air quality in Kearney. 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's critical 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 effort to pull air through the plugged-up filter.
Officials suggest checking your furnace filter every month and replacing it if it’s dirty. You’ll know if your filter needs changing because it will coated with dirt or dust. People who have dogs and cats will likely need to replace their furnace air filter more often, because an effective 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 located in the return air duct or blower compartment before the return air goes back into the furnace. This ensures air being pulled into the system is filtered before it moves through the furnace components and is heated.
Depending on the furnace brand, the filter may be located on the right, left, bottom or in some cases, within the furnace. It's generally housed inside of a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for details regarding filter location of your particular brand and model of furnace.
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 conditioning filter are effectively the same. 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 HVAC system.
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 flowing through your home is clean and safe.
What Are MERV Ratings and What MERV Rating Do I Need?
Once you track down your old furnace filter and figure out when it should be changed, it’s time to choose a replacement. That means deciding on the level of filtration that you need. One method to do this is by choosing an appropriate MERV rating for your needs.
MERV is an abbreviation for Minimum Efficiency Reporting Values. The MERV rating measures the effectiveness of air filters at trapping airborne contaminants. The rating scale ranges from 1 to 20, with bigger 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 unnecessarily restricting airflow. However, people with certain health conditions might need a a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or Air Conditioning System
Positioning an air filter in a furnace or air conditioner correctly 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 put in with this arrow pointing toward the furnace or AC, 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 toward the furnace or air conditioner.
Many people have difficulty remembering which direction to install their air filter. To help remember, consider snapping a quick photo with your cellular 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 point. A great time to ask about this is during a scheduled furnace maintenance visit.
How to Replace Your 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:
- Turn off your furnace: Be sure to switch 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 replacement filter to point the same way.
- Slide out the old filter: Be mindful not to knock out any dust or dirt.
- Note 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 the next change.
- 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 the dirty filter you just removed.
- 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 properly in place, 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 best things you can do to keep your system running efficiently.