Choosing the proper furnace filter and changing it when it becomes dirty is as important to your HVAC system as changing the oil is to your car. Each plays a crucial part in keeping its system running safely, efficiently and for a long time.
An overused furnace filter loses its effectiveness, permitting potentially harmful particles to flow through your home. It also limits airflow, which can damage your furnace and shorten its life span.
Making certain your furnace uses a clean filter that is appropriate for your needs is not just about keeping your furnace operating efficiently. It’s also about providing healthy indoor air quality for your residence.
Your health is important to the heating professionals at Haselhoff Air Solutions. We've long focused on enhancing indoor air quality in Ames. Here, we’ve answered common 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 important to replace dirty air filters in a furnace or air conditioner routinely. Soiled filters cause the system to worker harder than it should because it takes extra effort to pull air through the plugged-up filter.
Officials suggest 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. Homeowners who have pets that shed will very likely need 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 found in the return air duct or blower compartment before the return air goes back into the furnace. This ensures air being pulled into the system is filtered before it goes 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 typically housed within a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for important information concerning filter location of the furnace in your home.
Is My Furnace Filter Just a Type of Air Filter?
The simple answer is, yes. In HVAC, a furnace filter and an air filter or AC filter are effectively identical. While people may call them different things based on the current season— warm or chilly months—they are all filters that clean the air in your HVAC system.
They each eliminate 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 Are MERV Ratings and What MERV Rating Should I Have?
Once you track down your old furnace filter and decide 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 picking 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 molecules. The rating scale ranges from 1 to 20, with greater 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 some health conditions might need to use a filter with a higher MERV rating.
Where to Insert the Air Filter in a Furnace or Air Conditioner
Putting an air filter in a furnace or air conditioner properly is necessary for the efficient operation of the unit. Air filters are supposed to face a specific direction, indicated by an arrow located on the side of the filter frame. The filter should be put in with this arrow pointing at the furnace or AC, which is the direction of the airflow. If you're unsure about the airflow direction, try to remember that air always moves from the return duct to the heat or cooling source. Therefore, make sure the arrow points at the furnace or air conditioning unit.
Many people have difficulty remembering which direction to install their air filter. To help remember, consider taking a quick 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 perfect time to ask about this is during a regular furnace maintenance call.
How to Replace Your Furnace 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 take out a dirty air filter and swap it for a new one:
- Turn off your furnace: Make sure to shut off your furnace before starting up the process.
- Find 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.
- Slide out the old filter: Be mindful not to knock out any dust or particles.
- Note 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 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 nicely and close any latches or clips that hold it in place.
- Turn on your furnace: Once the clean filter is completely installed, you can turn your furnace back on.
Will a Dirty Air Filter Cause Problems for a Furnace?
The simple answer is, yes, a dirty air filter can cause a furnace to cease working or shorten its lifespan. Changing your furnace or air conditioner filter is one of the best things you can do to keep your system operating efficiently.