Picking out the correct 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 vital part in keeping its system working safely, efficiently and for a long time.
A dirty furnace filter loses its effectiveness, enabling potentially harmful particles to circulate through your home. It also restricts airflow, which can damage your furnace and reduce its life span.
Making certain your furnace uses a clean filter that is ideal for your needs is not just about keeping your furnace running efficiently. It’s also about providing good indoor air quality for your home.
The health of your family is important to the HVAC professionals at America's Green Heating & Air Conditioning. We've long worked with an eye on bettering indoor air quality in Frederick. Here, we’ve answered frequent 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'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 pull air through the plugged-up filter.
Officials recommend checking 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 that shed will probably need to replace their furnace air filter more often, because a quality 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 normally found in the return air duct or blower compartment before the return air gets to the furnace. This makes sure air flowing 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 found on the right, left, bottom or in some cases, within 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 about filter location of your particular brand and model of furnace.
Are Air Filters and Furnace Filters the Same Thing?
The easy 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 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 circulating throughout your home is clean and safe.
What Is a MERV Rating and What MERV Rating Should I Have?
Once you find your old furnace filter and decide when it should be changed, it’s time to select a replacement. That means deciding on the level of filtration that you need. One method to do this is by choosing an appropriate MERV rating for your needs.
MERV is short 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 an ideal balance between having good indoor air quality without needlessly restricting airflow. However, people with certain health conditions might need to purchase a filters with a higher MERV rating.
How to Place the Air Filter in a Furnace or Air Conditioning System
Putting an air filter in a furnace or air conditioner the proper way is necessary for the efficient operation of the unit. Air filters have a certain direction, indicated by an arrow printed 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 conditioning unit, which is the direction of the airflow. If you're doubtful 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, be sure that the arrow points at the furnace or air conditioner.
Many people have difficulty remembering which direction to install an air filter. To help remember, consider taking a picture with your cell phone after the filter has been correctly 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 inquire about this is during a regular furnace maintenance call.
How to Change a Furnace Air Filter
Changing the filter on your furnace or AC is a quick and easy process. Here is a step-by-step breakdown of how to retreive a dirty air filter and replace it with a new one:
- Turn off your furnace: Make a point to shut off your furnace before starting up the process.
- Look for the furnace filter: Typically, the filter is positioned 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 replacement filter to point similarly.
- Remove the old filter: Be diligent not to knock out any dust or debris.
- Document the date: Write down the date of replacement on the new filter's frame. This will make it easier to 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 old filter you are replacing.
- Secure the filter: Make sure the new filter fits nicely and close any latches or clips that lock it in the unit.
- Turn on your furnace: Once the new filter is safely installed, you can turn your furnace back on.
Can a Dirty Air Filter Damage My Furnace?
The short answer is, yes, a dirty air filter can cause a furnace to cease working or limit its lifespan. Changing your furnace or air conditioning filter is one of the easiest things you can do to keep your system operating efficiently.
