Choosing 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 critical 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 flow through your home. It also limits airflow, which can damage your furnace and reduce its life span.
Making sure 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 excellent indoor air quality for your residence.
The health of your family is important to the heating pros at A&A Air Conditioning, Heating & Sheet Metal. We've long been dedicated to bettering indoor air quality in Grass Valley. Here, we’ve answered common 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 important to replace dirty air filters in a furnace or air conditioner periodically. Soiled filters cause the system to worker harder than it should because it takes extra work to force air through the plugged-up filter.
Officials suggest inspecting your furnace filter every 30 days and replacing it if it’s dirty. You’ll know if your filter needs changing because it will be gray or black from dirt or dust. Those who have dogs and cats will probably want to replace their furnace air filter more often, because a good air filter will trap pet hair circulating in a home.
How to Find the 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 ensures air being pulled into the system is filtered before it passes through the furnace components and is heated.
Depending on the type of furnace, the filter may be positioned on the right, left, bottom or in some cases, on the inside of 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 your particular brand and model of furnace.
Is My Furnace Filter Just a Type of Air Filter?
The straightforward answer is, yes. In HVAC, a furnace filter and an air filter or air conditioner filter are effectively the same thing. While they might be called different things based on the current season— hot or cold—they are all filters that clean the air in your home.
They each get rid of dust, allergens, bacteria and other particulates from the air that is drawn into the furnace and air conditioning system, making sure the air flowing through your home is clean and safe.
What Is a MERV Rating and What MERV Rating Should I Have?
Once you track down your old furnace filter and figure out when it should be replaced, it’s time to pick a replacement. That means picking the level of filtration that you need. One method to do this is by selecting 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 molecules. The rating scale ranges from 1 to 20, with greater numbers indicating a greater ability to filter tinier particles.
Experts say a filter with a MERV rating between 8 and 13 offers an appropriate balance between having good indoor air quality without overly restricting airflow. However, people with some health conditions could need to purchase a filters with a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or AC Unit
Putting an air filter in a furnace or air conditioner correctly is crucial for the efficient operation of the unit. Air filters are designed to be installed in a particular direction, indicated by an arrow written on the side of the filter frame. The filter should be installed with this arrow pointing toward the furnace or air conditioning unit, which is the direction of the airflow. If you're unsure 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 at the furnace or air conditioner.
Many people struggle with which direction to face their air filter. To help remember, consider taking a quick picture with your cellular 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 handy time to do this is during a scheduled furnace maintenance appointment.
How to Replace Your Furnace Air Filter
Switching out the filter on your furnace or air conditioner is a simple process. Here is a step-by-step breakdown of how to remove a dirty air filter and exchange it for a new one:
- Turn off your furnace: Make sure to switch off your furnace before starting the process.
- Locate 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 similarly.
- Take out the old filter: Be diligent not to knock out any dust or particles.
- Record the date: Write down the date you changed filters on the new filter's frame. This will help your family 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 correctly and close any latches or clips that lock it in the unit.
- Turn on your furnace: Once the new filter is properly in place, 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 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 efficiently.