Choosing the right furnace filter and changing it when it gets 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.
A dirty furnace filter loses its effectiveness, allowing potentially harmful particles to move 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 ideal for your needs is not just about keeping your furnace working efficiently. It’s also about creating good indoor air quality for your home.
Your health is important to the heating pros at Precision Mechanical. We've long worked with an eye on bettering indoor air quality in Rapid City. Here, we’ve answered frequent questions about HVAC filters, including that particularly 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 vital to replace dirty air filters in a furnace or air conditioner periodically. Dirty filters cause the system to worker harder than it should because it takes extra effort to pull air through the plugged-up filter.
Officials advise 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 dogs and cats 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.
Locating Your Furnace's Air Filter
In general, a furnace air filter is normally installed in the return air duct or blower compartment before the return air reaches the furnace. This ensures air entering the system is filtered before it passes 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, inside the furnace. It's typically housed within a slot, frame or cabinet for easy access and replacement. Always refer to your furnace's owner manual for facts 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 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 home.
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 distributed throughout your home is clean and safe.
What Is the MERV Rating System and What MERV Rating Should I Have?
Once you track down your old furnace filter and determine when it should be substituted for a clean one, it’s time to select a replacement. That means determining the level of filtration that you need. One way to do that is by choosing an appropriate MERV rating for your needs.
MERV stands for Minimum Efficiency Reporting Values. The MERV rating calculates the effectiveness of air filters at trapping airborne contaminants. The rating scale ranges from 1 to 20, with greater numbers indicating a greater ability to filter smaller 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 certain health conditions might need to purchase a filters with a higher MERV rating.
Where to Insert the Air Filter in a Furnace or Air Conditioning System
Putting an air filter in a furnace or air conditioner properly is crucial for the efficient operation of the unit. Air filters have a certain 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 air conditioner, which is the direction of the airflow. If you're not sure about the airflow direction, it may be helpful to remember that air always moves from the return duct to the heat or cooling source. Therefore, make certain the arrow points in the direction of the furnace or air conditioning unit.
Many people are confused by which direction to install their air filter. To help remember, consider taking a picture with your cellular 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 handy time to do this is during a routine furnace maintenance call.
How to Change a Furnace Air Filter
Replacing the filter on your furnace or air conditioner is a quick and easy process. Here is a step-by-step breakdown of how to remove a dirty air filter and replace it with a new one:
- Turn off your furnace: Make a point to shut off your furnace before starting up the process.
- Locate the furnace filter: Typically, the filter is found within 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 replacement filter to point similarly.
- Remove the old filter: Be diligent 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 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 at 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 nicely and close any latches or clips that hold it in the unit.
- Turn on your furnace: Once the clean filter is properly installed, you can turn your furnace back on.
Will a Dirty Air Filter Damage My Furnace?
The simple answer is, yes, a dirty air filter can cause a furnace to quit working or limit its lifespan. Changing your furnace or air conditioning filter is one of the easiest things you can do to keep your system working effectively.
