Picking out the correct 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 crucial function in keeping its system working safely, efficiently and for a long time.
An overused furnace filter loses its effectiveness, permitting potentially harmful particles to circulate through your home. It also slows airflow, which can damage your furnace and reduce its life span.
Making sure your furnace uses a clean filter that is ideal for your needs is not merely about keeping your furnace working efficiently. It’s also about creating excellent indoor air quality for your household.
Your health is important to the heating professionals at Farnell Mechanical, Inc.. We've long been dedicated to enhancing indoor air quality in Auburn and Opelika. 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?
When to Replace the Air Filter in Your Furnace
Experts stress it's vital to replace dirty air filters in a furnace or air conditioner periodically. Dirty filters cause the system to worker harder than it should because it takes extra work to force air through the plugged-up filter.
Officials suggest checking your furnace filter every 30 days 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 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.
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 reaches the furnace. This is so air being pulled into the system is filtered before it moves through the furnace components and is heated.
Depending on the type of furnace, the filter may be located on the right, left, bottom or in some cases, on the inside of the furnace. It's usually housed inside of a slot, frame or cabinet for simple access and replacement. Always refer to your furnace's owner manual for important information regarding filter location of the furnace in your home.
Is My Furnace Filter Just a Type of Air Filter?
The easy answer is, yes. In HVAC, a furnace filter and an air filter or air conditioning filter are essentially the same. While people might refer to them differently based on the current season— summer or winter—they are all filters that clean the air in your home.
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 the MERV Rating System and What MERV Rating Do I Need?
Once you find your old furnace filter and determine when it should be substituted for a clean one, it’s time to select a replacement. That means picking the level of filtration that you need. One method to do this is by selecting 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 contaminants. The rating scale ranges from 1 to 20, with greater numbers indicating enhanced capabilities to filter tinier particles.
Experts say a filter with a MERV rating between 8 and 13 offers a good balance between having adequate indoor air quality without overly restricting airflow. However, people with certain health conditions may need a a higher MERV rating.
How to Place the Air Filter in a Furnace or AC Unit
Positioning an air filter in a furnace or air conditioner properly is necessary for the efficient operation of the unit. Air filters have 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 air conditioning unit, which is the direction of the airflow. If you're doubtful about the airflow direction, 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 conditioning unit.
Many people struggle with which direction to point their air filter. To help remember, consider snapping a quick photo with your cellular 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 go. A perfect time to ask about 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 quick and easy process. Here is a step-by-step list of how to remove a dirty air filter and replace it with a new one:
- Turn off your furnace: Make a point to turn off your furnace before beginning the process.
- Locate the furnace filter: Typically, the filter is found 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 new filter to point the same way.
- Take out the old filter: Be careful not to knock out any dust or particles.
- Document the date: Write down the date you changed filters on the new filter's frame. This will help you keep track of when it's time for another replacement.
- Put 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 dirty filter you just removed.
- Secure the filter: Make sure the new filter fits nicely and close any latches or clips that lock it in the compartment.
- Turn on your furnace: Once the new filter is properly installed, you can turn your furnace back on.
Will a Dirty Air Filter Cause Problems for a Furnace?
The short answer is, yes, a dirty air filter can cause a furnace to stop working or decrease its lifespan. Changing your furnace or air conditioning filter is one of the easiest things you can do to keep your system running efficiently.