Selecting the correct 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 vital part in keeping its system running 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 sure your furnace uses a clean filter that is suitable for your needs is not only about keeping your furnace working efficiently. It’s also about creating excellent indoor air quality for your residence.
The quality of the air your family breathes is important to the HVAC pros at Central Heating & Plumbing. We've long focused on improving indoor air quality in New Castle. Here, we’ve answered common 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?
It is critical 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 pull air through the plugged-up filter.
Officials recommend 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 be gray or black from dirt or dust. People who have pets will probably want to replace their furnace air filter more often, because an effective 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 usually installed in the return air duct or blower compartment before the return air goes back into 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 furnace brand, the filter may be positioned on the right, left, bottom or in some cases, within the furnace. It's generally housed inside of 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 conditioning filter are effectively the same. While people may call them different things 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 airborne debris from the air that is drawn into the furnace and air conditioning system, making certain the air flowing through your home is clean and safe.
What Are MERV Ratings and What MERV Rating Do I Need?
Once you track down your old furnace filter and determine when it should be substituted for a clean one, it’s time to pick a replacement. That means deciding on the level of filtration that you need. One approach to this is by choosing an appropriate MERV rating for your needs.
MERV is an abbreviation for Minimum Efficiency Reporting Values. The MERV rating calculates the effectiveness of air filters at trapping airborne particles. The rating scale ranges from 1 to 20, with greater numbers indicating enhanced capabilities to filter smaller particles.
Experts say a filter with a MERV rating between 8 and 13 offers an appropriate balance between having healthy indoor air quality without unnecessarily restricting airflow. However, people with specific health conditions could need to use a filter with a higher MERV rating.
Where to Insert the Air Filter in a Furnace or AC Unit
Putting an air filter in a furnace or air conditioner correctly is important for the efficient operation of the heating or cooling system. Air filters are designed to be installed in a particular direction, indicated by an arrow printed on the side of the filter frame. The filter should be installed with this arrow pointing at the furnace or air conditioning unit, which is the direction of the airflow. If you're unsure 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 sure the arrow points toward the furnace or air conditioning unit.
Many people are confused by which direction to face their air filter. To help remember, consider taking a quick picture with your mobile 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 point. A great time to ask about this is during a routine furnace maintenance appointment.
Changing Your Furnace's Air Filter
Changing the filter on your furnace or AC is an easy process. Here is a step-by-step list of how to take out a dirty air filter and swap it for a new one:
- Turn off your furnace: Make sure to turn off your furnace before starting up the process.
- Look for the furnace filter: Typically, the filter is positioned in the furnace or in the air return vent. Make note of which direction the arrow points on the filter, because you’ll want the arrow on the clean filter to point in the same direction.
- Take out the old filter: Be mindful not to knock out any dust or dirt.
- 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 the next change.
- 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 your last filter.
- Secure the filter: Make sure the new filter fits securely and close any latches or clips that secure it in the compartment.
- Turn on your furnace: Once the clean filter is properly installed, you can turn your furnace back on.
Will a Dirty Air Filter Damage My Furnace?
The shortest answer is, yes, a dirty air filter can cause a furnace to quit working or limit its lifespan. Changing your furnace or AC filter is one of the easiest things you can do to keep your system operating correctly.