Selecting the proper 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 function in keeping its system working safely, efficiently and for a long time.
An overused furnace filter loses its effectiveness, permitting potentially harmful particles to flow through your home. It also restricts airflow, which can damage your furnace and reduce its life span.
Ensuring your furnace uses a clean filter that is suitable for your needs is not merely about keeping your furnace running efficiently. It’s also about providing excellent indoor air quality for your household.
Your health is important to the heating and cooling professionals at Polar Air & Mechanical. We've long worked with an eye on enhancing indoor air quality in Myrtle Beach. 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 Should I Replace My Furnace Air Filter?
It's important 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 move air through the plugged-up filter.
Officials suggest checking your furnace filter every month 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. Homeowners who have dogs and cats will probably want to replace their furnace air filter more often, because an effective 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 installed in the return air duct or blower compartment before the return air reaches the furnace. This is so air entering the system is filtered before it goes through the furnace components and is heated.
Depending on the furnace brand, the filter may be positioned on the right, left, bottom or in some cases, inside 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 details concerning filter location of your 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 conditioning filter are essentially the same thing. 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 remove 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 a MERV Rating and What MERV Rating Do I Need?
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 deciding on 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 measures the effectiveness of air filters at trapping airborne molecules. The rating scale ranges from 1 to 20, with higher numbers indicating a greater ability to filter tinier particles.
Experts say a filter with a MERV rating between 8 and 13 offers an ideal balance between having adequate indoor air quality without needlessly restricting airflow. However, people with some health conditions may need a a higher MERV rating.
How to Place the Air Filter in a Furnace or AC Unit
Putting an air filter in a furnace or air conditioner the proper way is crucial for the efficient operation of the unit. Air filters are designed to be installed in a certain direction, indicated by an arrow printed on the side of the filter frame. The filter should be installed with this arrow pointing in the direction of 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, make certain the arrow points in the direction of the furnace or air conditioning unit.
Many people struggle with which direction to install their air filter. To help remember, consider taking a quick 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 go. A handy time to ask about this is during a regular furnace maintenance appointment.
How to Change a Furnace Air Filter
Replacing the filter on your furnace or air conditioner is a simple process. Here is a step-by-step list of how to remove a dirty air filter and exchange it for a new one:
- Turn off your furnace: Make sure to turn off your furnace before beginning the process.
- Look for 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 replacement filter to point in the same direction.
- Take out the old filter: Be careful not to knock out any dust or particles.
- Document 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 another replacement.
- Put in new filter: Put in the new filter with the arrow pointing in the direction of 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 secure it in place.
- Turn on your furnace: Once the replacement filter is completely in place, 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 reduce its lifespan. Changing your furnace or air conditioning filter is one of the best things you can do to keep your system working effectively.
