Picking out the correct furnace filter and changing it when it is dirty is as important to your HVAC system as changing the oil is to your car. Each plays a critical part in keeping its system running safely, efficiently and for a long time.
An overused furnace filter loses its effectiveness, permitting potentially harmful particles to circulate 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 ideal for your needs is not just about keeping your furnace working efficiently. It’s also about creating healthy indoor air quality for your home.
Your health is important to the HVAC specialists at A2Z Air Inc. We've long worked with an eye on improving indoor air quality in Boynton Beach. Here, we’ve answered common questions about HVAC filters, including that especially tricky question of what direction do you point a filter in your furnace or air conditioner?
When Should I Replace My Furnace Air Filter?
Experts stress it's 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 move air through the plugged-up filter.
Officials recommend checking 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. Homeowners who have dogs and cats will probably have 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 commonly located in the return air duct or blower compartment before the return air goes back into 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 located on the right, left, bottom or in some cases, on the inside of the furnace. It's generally housed inside of a slot, frame or cabinet for easy access and replacement. Always refer to your furnace's owner manual for details about filter location of your furnace.
Is a Furnace Filter the Same as an Air Filter?
The easy answer is, yes. In HVAC, a furnace filter and an air filter or air conditioner filter are basically identical. 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 residence.
They each remove dust, allergens, bacteria and other contaminants 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 Do I Need?
Once you find your old furnace filter and decide when it should be changed, it’s time to select a replacement. That means deciding on the level of filtration that you need. One approach to this is by picking 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 bigger numbers indicating the power to filter smaller particles.
Experts say a filter with a MERV rating between 8 and 13 offers an appropriate balance between having healthy indoor air quality without unnecessarily restricting airflow. However, people with some health conditions could need to use a filter with a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or Air Conditioner
Putting 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 installed with this arrow pointing at the furnace or air conditioning unit, which is the direction of the airflow. If you're unsure about the airflow direction, try to remember that air always moves from the return duct to the heat or cooling source. Therefore, be sure that the arrow points at the furnace or AC.
Many people have difficulty remembering which direction to point their system's air filter. To help remember, consider taking a picture with your cell 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 point. A great time to do this is during a regular furnace maintenance call.
Changing Your Furnace's Air Filter
Switching out the filter on your furnace or AC is a quick and easy process. Here is a step-by-step rundown of how to take out a dirty air filter and replace it with a new one:
- Turn off your furnace: Be sure to shut off your furnace before starting up the process.
- Find the furnace filter: Typically, the filter is located in 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.
- Remove the old filter: Be careful not to knock out any dust or dirt.
- 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.
- Slide 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 dirty filter you just removed.
- Secure the filter: Make sure the new filter fits correctly and close any latches or clips that secure it in the compartment.
- Turn on your furnace: Once the new filter is safely secured, you can turn your furnace back on.
Can a Dirty Air Filter Damage My Furnace?
The short answer is, yes, a dirty air filter can cause a furnace to cease working or decrease its lifespan. Changing your furnace or AC filter is one of the simplest things you can do to keep your system operating effectively.
