Choosing the right 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 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 limits airflow, which can damage your furnace and decrease its life span.
Making sure your furnace uses a clean filter that is suitable for your needs is not just about keeping your furnace running efficiently. It’s also about providing healthy indoor air quality for your residence.
The health of your family is important to the heating specialists at Temperature Doctors Heating & Cooling. We've long worked with an eye on bettering indoor air quality in Rockford. 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?
It is critical 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 more energy to pull air through the plugged-up filter.
Officials suggest 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 filled with dirt or dust. Those who have dogs and cats will very 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 usually located in the return air duct or blower compartment before the return air goes back into the furnace. This is so 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 typically housed in a slot, frame or cabinet for simple access and replacement. Always refer to your furnace's owner manual for important information concerning filter location of your 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 air conditioner 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 residence.
They each eliminate dust, allergens, bacteria and other contaminants 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 Is the MERV Rating System and What MERV Rating Do I Need?
Once you locate your old furnace filter and determine when it should be substituted for a clean one, it’s time to choose 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 short for Minimum Efficiency Reporting Values. The MERV rating measures 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 an ideal balance between having good indoor air quality without unnecessarily restricting airflow. However, people with some health conditions may need a a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or Air Conditioner
Positioning an air filter in a furnace or air conditioner properly is crucial for the efficient operation of the heating or cooling system. Air filters are designed to be installed in a specific direction, indicated by an arrow located on the side of the filter frame. The filter should be installed 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, remember that air always moves from the return duct and then to the heat or cooling source. Therefore, make certain the arrow points in the direction of the furnace or AC.
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 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 go. A great time to ask about this is during a scheduled furnace maintenance call.
Changing Your Furnace's Air Filter
Switching out the filter on your furnace or AC is an easy process. Here is a step-by-step rundown of how to take out a dirty air filter and exchange it for a new one:
- Turn off your furnace: Make a point to turn off your furnace before beginning the process.
- Locate the furnace filter: Typically, the filter is located within the furnace or in the air return vent. Make a mental note or write down which direction the arrow points on the filter, because you’ll want the arrow on the replacement filter to point in the same direction.
- Slide out the old filter: Be careful 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 help your family 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 your last filter.
- Secure the filter: Make sure the new filter fits nicely and close any latches or clips that lock it in the compartment.
- Turn on your furnace: Once the new filter is safely installed, you can turn your furnace back on.
Can a Dirty Air Filter Cause a Furnace Not to Work?
The shortest answer is, yes, a dirty air filter can cause a furnace to cease working or limit its lifespan. Changing your furnace or AC filter is one of the simplest things you can do to keep your system operating efficiently.