Selecting the right 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 function in keeping its system working safely, efficiently and for a long time.
A clogged furnace filter loses its effectiveness, permitting potentially harmful particles to flow through your home. It also slows airflow, which can damage your furnace and decrease its life span.
Ensuring your furnace uses a clean filter that is suitable for your needs is not only about keeping your furnace running efficiently. It’s also about providing good indoor air quality for your residence.
The quality of the air your family breathes is important to the heating and cooling pros at Stieferman Heating Company Inc. We've long worked with an eye on bettering indoor air quality in Jefferson City. Here, we’ve answered common questions about HVAC filters, including that particularly 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. Dirt-clogged filters cause the system to worker harder than it should because it takes extra work to move air through the plugged-up filter.
Officials suggest examining your furnace filter every month and replacing it if it’s dirty. You’ll know if the filter needs to be changed because it will coated with dirt or dust. Those who have pets will likely have to replace their furnace air filter more often, because a quality 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 gets to 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 type of furnace, the filter may be positioned on the right, left, bottom or in some cases, on the inside of the furnace. It's usually housed in a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for information regarding filter location of your particular brand and model of furnace.
Is a Furnace Filter the Same as an Air Filter?
The easy answer is, yes. In HVAC, a furnace filter and an air filter or air conditioner filter are basically identical. While people might refer to them differently based on the current season— warm or chilly months—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, making sure the air distributed throughout your home is clean and safe.
What Is a MERV Rating and What MERV Rating Do I Need?
Once you find your old furnace filter and decide 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 selecting an appropriate MERV rating for your needs.
MERV is an abbreviation for Minimum Efficiency Reporting Values. The MERV rating indicates the effectiveness of air filters at trapping airborne contaminants. The rating scale ranges from 1 to 20, with greater numbers indicating the power to filter small 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 to purchase a filters with a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or Air Conditioner
Putting an air filter in a furnace or air conditioner properly is important for the efficient operation of the system. 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 toward the furnace or air conditioning unit, which is the direction of the airflow. If you're unsure about the airflow direction, remember that air always moves from the return duct and then to the heat or cooling source. Therefore, make certain the arrow points toward the furnace or AC.
Many people struggle with which direction to point an air filter. To help remember, consider taking a quick picture with your cell 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 handy time to do this is during a scheduled furnace maintenance call.
How to Change a Furnace Air Filter
Changing 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:
- 1. Turn off your furnace: Make sure to turn off your furnace before starting up the process.
- Locate the furnace filter: Typically, the filter is positioned in 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 diligent not to knock out any dust or dirt.
- Note the date: Write down the date of replacement on the new filter's frame. This will help you 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 in the direction of 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 replacement filter is safely in place, 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 stop 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.