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 vital function in keeping its system operating safely, efficiently and for a long time.
A dirty furnace filter loses its effectiveness, allowing 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 merely about keeping your furnace running efficiently. It’s also about providing excellent indoor air quality for your residence.
The health of your family is important to the heating professionals at Thurston Heating & Air Conditioning. We've long been dedicated to bettering indoor air quality in Kearney. Here, we’ve answered frequent questions about HVAC filters, including that very tricky question of what direction do you point a filter in your furnace or air conditioner?
When to Replace the Air Filter in Your Furnace
It is critical to replace dirty air filters in a furnace or air conditioner periodically. Dirt-clogged filters cause the system to worker harder than it should because it takes more energy to force air through the plugged-up filter.
Officials recommend inspecting your furnace filter every 30 days and replacing it if it’s dirty. You’ll know if the filter needs to be changed because it will filled with dirt or dust. People who have dogs and cats will likely want to replace their furnace air filter more often, because an effective air filter will trap pet hair circulating in a home.
Locating Your Furnace's Air Filter
In general, a furnace air filter is commonly found in the return air duct or blower compartment before the return air gets to the furnace. This ensures air entering the system is filtered before it moves through the furnace components and is heated.
Depending on the furnace model, the filter may be located on the right, left, bottom or in some cases, on the inside of the furnace. It's usually housed inside of a slot, frame or cabinet for easy access and replacement. Always refer to your furnace's owner manual for information concerning filter location of your particular brand and model of furnace.
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 air conditioner filter are effectively the same thing. 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, making sure the air circulating throughout your home is clean and safe.
What Is the MERV Rating System and What MERV Rating Do I Need?
Once you track down your old furnace filter and determine when it should be changed, it’s time to pick 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 is short for Minimum Efficiency Reporting Values. The MERV rating measures the effectiveness of air filters at trapping airborne particles. The rating scale ranges from 1 to 20, with higher numbers indicating the power to filter tinier particles.
Experts say a filter with a MERV rating between 8 and 13 offers an ideal balance between having healthy indoor air quality without needlessly restricting airflow. However, people with specific health conditions may need to use a filter with a higher MERV rating.
Where to Insert the Air Filter in a Furnace or AC Unit
Positioning an air filter in a furnace or air conditioner the proper way is important for the efficient operation of the unit. Air filters have a specific direction, indicated by an arrow printed on the side of the filter frame. The filter should be installed with this arrow pointing toward the furnace or AC, which is the direction of the airflow. If you're not sure about the airflow direction, try 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 in the direction of the furnace or air conditioning unit.
Many people have difficulty remembering which direction to face their air filter. To help remember, consider taking a picture with your mobile phone after the filter has been properly 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 scheduled furnace maintenance visit.
Changing Your Furnace's Air Filter
Changing the filter on your furnace or air conditioner is a simple 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 a point to turn off your furnace before beginning the process.
- Look for the furnace filter: Typically, the filter is positioned within 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 new filter to point the same way.
- Remove the old filter: Be mindful not to knock out any dust or debris.
- Note 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 at the furnace, which is the direction of airflow and should be the same direction the arrow pointed on the dirty filter you just removed.
- Secure the filter: Make sure the new filter fits nicely and close any latches or clips that hold it in the unit.
- Turn on your furnace: Once the clean filter is completely secured, you can turn your furnace back on.
Will a Dirty Air Filter Cause a Furnace Not to Work?
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 simplest things you can do to keep your system running correctly.