Selecting the right 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 working safely, efficiently and for a long time.
A dirty furnace filter loses its effectiveness, enabling potentially harmful particles to move through your home. It also limits airflow, which can damage your furnace and decrease its life span.
Ensuring your furnace uses a clean filter that is appropriate for your needs is not merely about keeping your furnace working efficiently. It’s also about delivering good indoor air quality for your home.
The health of your family is important to the heating and cooling professionals at Precision Mechanical. We've long been dedicated to improving indoor air quality in Rapid City. 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
Experts stress it's critical to replace dirty air filters in a furnace or air conditioner routinely. Dirt-clogged filters cause the system to worker harder than it should because it takes extra effort to force air through the plugged-up filter.
Officials suggest inspecting your furnace filter every month and replacing it if it’s dirty. You’ll know if it is dirty because it will filled with dirt or dust. Homeowners who have pets will probably want to replace their furnace air filter more often, because a quality 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 reaches the furnace. This makes sure air entering the system is filtered before it goes through the furnace components and is heated.
Depending on the type of furnace, the filter may be located on the right, left, bottom or in some cases, within the furnace. It's generally housed within a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for facts regarding filter location of the furnace in your home.
Is a Furnace Filter the Same as an Air Filter?
The simple answer is, yes. In HVAC, a furnace filter and an air filter or air conditioning filter are basically the same thing. While they might be called 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 particulates 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 MERV Rating Do I Need?
Once you locate your old furnace filter and decide when it should be substituted for a clean one, it’s time to choose a replacement. That means picking the level of filtration that you need. One way to do that 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 higher numbers indicating enhanced capabilities to filter tinier particles.
Experts say a filter with a MERV rating between 8 and 13 offers a good balance between having healthy indoor air quality without unnecessarily restricting airflow. However, people with some health conditions may need to purchase a filters with a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or Air Conditioning System
Installing an air filter in a furnace or air conditioner the proper way is important for the efficient operation of the heating or cooling system. Air filters are supposed to face a certain direction, indicated by an arrow located on the side of the filter frame. The filter should be placed in the unit 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, remember that air always moves from the return duct and then to the heat or cooling source. Therefore, be sure that the arrow points at the furnace or AC.
Many people struggle with which direction to point their 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 great time to inquire about this is during a regular furnace maintenance appointment.
Changing Your Furnace's Air Filter
Replacing the filter on your furnace or air conditioner is a simple process. Here is a step-by-step rundown of how to take out a dirty air filter and swap it for a new one:
- Turn off your furnace: Be sure to shut off your furnace before beginning the process.
- Find the furnace filter: Typically, the filter is found 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.
- Take out the old filter: Be careful not to knock out any dust or debris.
- Note the date: Write down the date you changed filters on the new filter's frame. This will help you keep track of when it's time for the next change.
- 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 the old filter you are replacing.
- Secure the filter: Make sure the new filter fits securely and close any latches or clips that hold it in place.
- Turn on your furnace: Once the replacement filter is safely secured, 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 cease working or decrease its lifespan. Changing your furnace or air conditioner filter is one of the best things you can do to keep your system operating correctly.
