Choosing 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 function in keeping its system operating safely, efficiently and for a long time.
A dirty furnace filter loses its effectiveness, permitting potentially harmful particles to move through your home. It also slows 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 operating efficiently. It’s also about creating excellent indoor air quality for your household.
The health of your family is important to the heating pros at Enertek Air Conditioning & Heating. We've long worked with an eye on improving indoor air quality in Northridge. Here, we’ve answered frequent 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?
It's vital 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 extra work to move 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 be gray or black from dirt or dust. Those who have pets will likely need to replace their furnace air filter more often, because a good 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 normally found in the return air duct or blower compartment before the return air goes back into the furnace. This makes sure 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 typically housed inside of a slot, frame or cabinet for easy access and replacement. Always refer to your furnace's owner manual for important information concerning filter location of the furnace in your home.
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 home.
They each eliminate dust, allergens, bacteria and other contaminants from the air that is drawn into the furnace and air conditioning system, ensuring the air distributed throughout your home is clean and safe.
What Is the MERV Rating System and What Rating Is Best for Me?
Once you locate your old furnace filter and decide when it should be substituted for a clean one, it’s time to pick a replacement. That means deciding on the level of filtration that you need. One method to do this is by picking an appropriate MERV rating for your needs.
MERV is an abbreviation for Minimum Efficiency Reporting Values. The MERV rating indicates the effectiveness of air filters at trapping airborne contaminants. The rating scale ranges from 1 to 20, with greater numbers indicating enhanced capabilities to filter small particles.
Experts say a filter with a MERV rating between 8 and 13 offers an ideal balance between having healthy indoor air quality without overly restricting airflow. However, people with some 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 the proper way is important for the efficient operation of the system. Air filters are supposed to face a certain direction, indicated by an arrow written on the side of the filter frame. The filter should be put in with this arrow pointing toward the furnace or air conditioner, which is the direction of the airflow. If you're unsure about the airflow direction, it may be helpful to remember that air always moves from the return duct and then to the heat or cooling source. Therefore, make sure the arrow points in the direction of the furnace or AC.
Many people are confused by which direction to install their air filter. To help remember, consider taking a quick 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 great time to do this is during a scheduled furnace maintenance visit.
Changing Your Furnace's Air Filter
Changing 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 replace it with a new one:
- Turn off your furnace: Make sure to switch off your furnace before starting the process.
- Find the furnace filter: Typically, the filter is located in 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 in the same direction.
- Remove the old filter: Be mindful not to knock out any dust or particles.
- Note 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 you to change it again.
- Insert 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 your last filter.
- Secure the filter: Make sure the new filter fits securely and close any latches or clips that hold it in the unit.
- Turn on your furnace: Once the clean filter is safely secured, 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 stop working or limit its lifespan. Changing your furnace or air conditioner filter is one of the best things you can do to keep your system running efficiently.
