Selecting the ideal 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 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 move through your home. It also restricts airflow, which can damage your furnace and reduce its life span.
Ensuring your furnace uses a clean filter that is ideal for your needs is not just about keeping your furnace working efficiently. It’s also about delivering good indoor air quality for your residence.
Your health is important to the heating pros at Dave's Diversified Services. We've long worked with an eye on improving indoor air quality in Front Royal. 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 Should I Replace My Furnace Air Filter?
Experts stress it's vital to replace dirty air filters in a furnace or air conditioner regularly. Dirty filters cause the system to worker harder than it should because it takes more energy to pull air through the plugged-up filter.
Officials suggest examining your furnace filter monthly and replacing it if it’s dirty. You’ll know if it is dirty because it will be gray or black from dirt or dust. Those who have pets will very likely have to replace their furnace air filter more often, because a good 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 reaches the furnace. This ensures air flowing into the system is filtered before it goes through the furnace components and is heated.
Depending on the type of furnace, the filter may be found on the right, left, bottom or in some cases, on the inside of the furnace. It's generally housed in a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for important information regarding filter location of your 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 AC filter are basically 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 residence.
They each get rid of dust, allergens, bacteria and other airborne debris 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 Are MERV Ratings and What MERV Rating Do I Need?
Once you find your old furnace filter and figure out when it should be changed, it’s time to choose a replacement. That means determining the level of filtration that you need. One approach to this is by choosing an appropriate MERV rating for your needs.
MERV stands 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 higher numbers indicating a greater ability to filter tinier particles.
Experts say a filter with a MERV rating between 8 and 13 offers a good balance between having good indoor air quality without unnecessarily restricting airflow. However, people with specific health conditions may need to use a filter with a higher MERV rating.
How to Place the Air Filter in a Furnace or Air Conditioning System
Positioning an air filter in a furnace or air conditioner the proper way is important for the efficient operation of the heating or cooling system. Air filters have 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 conditioner, which is the direction of the airflow. If you're not sure about the airflow direction, remember that air always moves from the return duct to the heat or cooling source. Therefore, make certain the arrow points toward the furnace or air conditioning unit.
Many people struggle with which direction to face their system's air filter. To help remember, consider taking a quick 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 go. A handy time to do this is during a routine furnace maintenance appointment.
How to Change a Furnace Air Filter
Replacing the filter on your furnace or air conditioning system is an easy process. Here is a step-by-step breakdown of how to remove a dirty air filter and swap it for a new one:
- Turn off your furnace: Be sure to turn off your furnace before starting the process.
- Look for the furnace filter: Typically, the filter is found inside 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 clean filter to point the same way.
- Remove the old filter: Be mindful not to knock out any dust or particles.
- Note 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 the next change.
- 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 old filter you are replacing.
- Secure the filter: Make sure the new filter fits nicely and close any latches or clips that secure it in the unit.
- Turn on your furnace: Once the clean filter is completely in place, you can turn your furnace back on.
Will 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 shorten its lifespan. Changing your furnace or air conditioning filter is one of the easiest things you can do to keep your system running effectively.