Choosing the proper 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.
A dirty furnace filter loses its effectiveness, allowing potentially harmful particles to move through your home. It also slows airflow, which can damage your furnace and shorten its life span.
Making sure your furnace uses a clean filter that is ideal for your needs is not merely about keeping your furnace operating efficiently. It’s also about providing healthy indoor air quality for your household.
The health of your family is important to the heating pros at MPC Heating & Cooling. We've long focused on bettering indoor air quality in Chadron. Here, we’ve answered frequent questions about HVAC filters, including that especially 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 vital 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 advise inspecting your furnace filter monthly and replacing it if it’s dirty. You’ll know if the filter needs to be changed because it will be gray or black from dirt or dust. People who have pets will very likely want 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 usually located in the return air duct or blower compartment before the return air goes back into the furnace. This is so air flowing into the system is filtered before it passes 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, on the inside of the furnace. It's typically housed within a slot, frame or cabinet for easy access and replacement. Always refer to your furnace's owner manual for details about filter location of your furnace.
Are Air Filters and Furnace Filters the Same Thing?
The straightforward answer is, yes. In HVAC, a furnace filter and an air filter or AC filter are effectively identical. 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 eliminate 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 Should I Have?
Once you find your old furnace filter and determine when it should be replaced, it’s time to pick a replacement. That means deciding on the level of filtration that you need. One method to do this is by picking an appropriate MERV rating for your needs.
MERV is short 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 a good balance between having adequate indoor air quality without unnecessarily restricting airflow. However, people with specific health conditions could need to purchase a filters with a higher MERV rating.
Where to Insert the Air Filter in a Furnace or Air Conditioning System
Putting 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 placed in the unit with this arrow pointing toward the furnace or AC, which is the direction of the airflow. If you're unsure 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 AC.
Many people struggle with which direction to face an air filter. To help remember, consider snapping a quick photo with your cellular 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 point. A handy time to ask about this is during a routine furnace maintenance visit.
How to Replace Your Furnace Air Filter
Replacing the filter on your furnace or AC 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 shut off your furnace before starting the process.
- Locate the furnace filter: Typically, the filter is positioned inside the furnace or in the air return vent. Make a mental note or write down which direction the arrow points on the filter, because you’ll want the arrow on the replacement filter to point similarly.
- Slide out the old filter: Be diligent not to knock out any dust or dirt.
- Document the date: Write down the date you replaced the filter on the new filter's frame. This will make it easier to 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 completely installed, you can turn your furnace back on.
Can a Dirty Air Filter Cause a Furnace Not to Work?
The simple answer is, yes, a dirty air filter can cause a furnace to quit working or decrease its lifespan. Changing your furnace or air conditioner filter is one of the best things you can do to keep your system working efficiently.