Picking out 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 vital part in keeping its system running safely, efficiently and for a long time.
A clogged 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 certain your furnace uses a clean filter that is appropriate for your needs is not just about keeping your furnace running efficiently. It’s also about delivering healthy indoor air quality for your residence.
The quality of the air your family breathes is important to the heating specialists at Bishop’s HVAC. We've long been dedicated to enhancing indoor air quality in Sacramento. Here, we’ve answered common questions about HVAC filters, including that particularly tricky question of what direction do you point a filter in your furnace or air conditioner?
How Often to Replace the Air Filter in a Furnace
It is important to replace dirty air filters in a furnace or air conditioner regularly. 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 suggest inspecting your furnace filter monthly and replacing it if it’s dirty. You’ll know if the filter needs to be changed because it will coated with dirt or dust. Those who have pets will likely want to replace their furnace air filter more often, because a quality 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 located in the return air duct or blower compartment before the return air goes back into the furnace. This is so air flowing into the system is filtered before it moves 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 convenient access and replacement. Always refer to your furnace's owner manual for information concerning filter location of your particular brand and model of 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 AC filter are effectively the same. 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 certain the air circulating throughout your home is clean and safe.
What Are MERV Ratings and What MERV Rating Do I Need?
Once you find your old furnace filter and decide when it should be replaced, it’s time to select a replacement. That means determining the level of filtration that you need. One approach to this is by choosing an appropriate MERV rating for your needs.
MERV is short for Minimum Efficiency Reporting Values. The MERV rating calculates the effectiveness of air filters at trapping airborne particles. The rating scale ranges from 1 to 20, with greater 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 adequate indoor air quality without overly restricting airflow. However, people with certain health conditions could need to purchase a filters with a higher MERV rating.
Where to Insert the Air Filter in a Furnace or AC Unit
Positioning an air filter in a furnace or air conditioner properly is crucial for the efficient operation of the system. 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 placed in the unit with this arrow pointing toward the furnace or AC, 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 and then to the heat or cooling source. Therefore, make certain the arrow points toward the furnace or air conditioner.
Many people are confused by which direction to face an air filter. To help remember, consider taking a quick picture with your cellular 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 handy time to ask about this is during a routine furnace maintenance call.
Changing Your Furnace's Air Filter
Switching out the filter on your furnace or AC is a simple process. Here is a step-by-step list of how to retreive a dirty air filter and replace it with a new one:
- Turn off your furnace: Be sure to turn off your furnace before starting the process.
- Look for 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 new filter to point the same way.
- Remove the old filter: Be mindful not to knock out any dust or dirt.
- Record the date: Write down the date of replacement on the new filter's frame. This will help you 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 securely and close any latches or clips that hold it in the compartment.
- Turn on your furnace: Once the replacement filter is completely secured, you can turn your furnace back on.
Can a Dirty Air Filter Cause Problems for a Furnace?
The simple 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 working efficiently.