Choosing the proper furnace filter and changing it when it is dirty is as important to your HVAC system as changing the oil is to your car. Each plays a critical part in keeping its system working safely, efficiently and for a long time.
An overused furnace filter loses its effectiveness, enabling potentially harmful particles to flow through your home. It also limits airflow, which can damage your furnace and reduce its life span.
Making certain your furnace uses a clean filter that is suitable for your needs is not just about keeping your furnace running efficiently. It’s also about creating excellent indoor air quality for your household.
The quality of the air your family breathes is important to the HVAC professionals at Western Mechanical, Inc.. We've long worked with an eye on improving indoor air quality in Cache Valley. 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?
When Should I Replace My Furnace Air Filter?
Experts stress 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 force 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 be gray or black from dirt or dust. People who have pets will probably have to replace their furnace air filter more often, because a good air filter will trap pet hair circulating in a home.
Locating Your Furnace's Air Filter
In general, a furnace air filter is normally found in the return air duct or blower compartment before the return air reaches the furnace. This ensures air entering the system is filtered before it passes 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, within the furnace. It's generally housed within a slot, frame or cabinet for easy access and replacement. Always refer to your furnace's owner manual for facts about 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— 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 distributed 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 decide when it should be replaced, it’s time to select a replacement. That means picking the level of filtration that you need. One method to do 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 contaminants. 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 overly restricting airflow. However, people with certain health conditions may need to use a filter 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 the proper way is crucial for the efficient operation of the system. Air filters are designed to be installed in a particular direction, indicated by an arrow located 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 conditioner, which is the direction of the airflow. If you're not sure about the airflow direction, it may be helpful to remember that air always moves from the return duct and then to the heat or cooling source. Therefore, make certain the arrow points at the furnace or air conditioner.
Many people struggle with which direction to face their air filter. To help remember, consider taking a picture 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 great time to do this is during a regular furnace maintenance call.
How to Change a Furnace Air Filter
Switching out the filter on your furnace or air conditioner is a simple process. Here is a step-by-step breakdown of how to take out a dirty air filter and exchange it for a new one:
- Turn off your furnace: Be sure to shut off your furnace before starting the process.
- Look for the furnace filter: Typically, the filter is located 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 replacement filter to point similarly.
- 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 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 replacement filter is properly installed, you can turn your furnace back on.
Will a Dirty Air Filter Damage My Furnace?
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 simplest things you can do to keep your system running efficiently.