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 critical function in keeping its system working safely, efficiently and for a long time.
A clogged furnace filter loses its effectiveness, allowing potentially harmful particles to circulate through your home. It also restricts airflow, which can damage your furnace and shorten its life span.
Making sure 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 delivering healthy indoor air quality for your residence.
The quality of the air your family breathes is important to the heating and cooling professionals at Rapids Sheet Metal Works Inc. We've long worked with an eye on enhancing indoor air quality in Wisconsin Rapids. 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. 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 recommend examining your furnace filter every 30 days and replacing it if it’s dirty. You’ll know if it is dirty because it will coated with dirt or dust. People who have pets that shed will likely need to replace their furnace air filter more often, because a quality air filter will trap pet hair circulating in a home.
Locating Your Furnace's Air Filter
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 makes sure air being pulled into the system is filtered before it moves through the furnace components and is heated.
Depending on the furnace model, the filter may be found on the right, left, bottom or in some cases, within the furnace. It's usually housed within a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for facts about filter location of your particular brand and model of furnace.
Are Air Filters and Furnace Filters the Same Thing?
The straightforward answer is, yes. In HVAC, a furnace filter and an air filter or air conditioner filter are effectively identical. While people may call them different things based on the current season— hot or cold—they are all filters that clean the air in your home.
They each eliminate dust, allergens, bacteria and other contaminants from the air that is drawn into the furnace and air conditioning system, making sure the air circulating throughout your home is clean and safe.
What Are MERV Ratings and What Rating Is Best for Me?
Once you track down your old furnace filter and figure out when it should be changed, it’s time to select a replacement. That means determining the level of filtration that you need. One method to do 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 bigger numbers indicating enhanced capabilities to filter small 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 certain health conditions might need to purchase a filters with a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or AC Unit
Positioning an air filter in a furnace or air conditioner correctly is important for the efficient operation of the unit. Air filters are supposed to face 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 doubtful about the airflow direction, remember that air always moves from the return duct to the heat or cooling source. Therefore, be sure that the arrow points toward the furnace or AC.
Many people struggle with which direction to face an air filter. To help remember, consider taking a picture with your mobile 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 be installed. A perfect time to inquire about this is during a scheduled furnace maintenance appointment.
Changing Your Furnace's Air Filter
Switching out the filter on your furnace or air conditioning system is a quick and easy process. Here is a step-by-step list of how to remove a dirty air filter and exchange it for a new one:
- Turn off your furnace: Be sure to switch off your furnace before beginning the process.
- Look for the furnace filter: Typically, the filter is located inside 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 new filter to point in the same direction.
- Take out the old filter: Be careful not to knock out any dust or dirt.
- Document the date: Write down the date you replaced the filter on the new filter's frame. This will make it easier to 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 toward 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 hold it in the unit.
- Turn on your furnace: Once the replacement filter is completely installed, you can turn your furnace back on.
Will a Dirty Air Filter Damage My Furnace?
The short answer is, yes, a dirty air filter can cause a furnace to stop working or decrease its lifespan. Changing your furnace or air conditioning filter is one of the best things you can do to keep your system running effectively.