Picking out 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 crucial part in keeping its system working safely, efficiently and for a long time.
A dirty furnace filter loses its effectiveness, allowing potentially harmful particles to circulate through your home. It also limits airflow, which can damage your furnace and shorten its life span.
Ensuring your furnace uses a clean filter that is ideal for your needs is not just about keeping your furnace running efficiently. It’s also about delivering excellent indoor air quality for your household.
The quality of the air your family breathes is important to the heating and cooling professionals at Dial One Mears Air Conditioning & Heating Inc. We've long focused on bettering indoor air quality in Phoenix. 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?
When to Replace the Air Filter in Your Furnace
It is vital to replace dirty air filters in a furnace or air conditioner routinely. Dirt-clogged filters cause the system to worker harder than it should because it takes extra work to pull 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 the filter needs to be changed because it will be gray or black from dirt or dust. Those who have pets that shed 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 commonly found in the return air duct or blower compartment before the return air gets to the furnace. This is so air flowing into the system is filtered before it passes through the furnace components and is heated.
Depending on the furnace model, the filter may be found on the right, left, bottom or in some cases, inside the furnace. It's usually housed in a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for facts regarding filter location of the furnace in your home.
Are Air Filters and Furnace Filters the Same Thing?
The straightforward answer is, yes. In HVAC, a furnace filter and an air filter or air conditioner filter are effectively identical. While people might refer to them differently based on the current season— warm or chilly months—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 flowing through 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 changed, it’s time to choose a replacement. That means picking the level of filtration that you need. One method to do this is by picking an appropriate MERV rating for your needs.
MERV is short for Minimum Efficiency Reporting Values. The MERV rating indicates the effectiveness of air filters at trapping airborne molecules. The rating scale ranges from 1 to 20, with higher numbers indicating the power to filter small particles.
Experts say a filter with a MERV rating between 8 and 13 offers a good balance between having good indoor air quality without needlessly restricting airflow. However, people with specific health conditions might need a a higher MERV rating.
Where to Insert 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 unit. Air filters have a specific 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 in the direction of the furnace or air conditioner, which is the direction of the airflow. If you're unsure about the airflow direction, remember that air always moves from the return duct towards the heat or cooling source. Therefore, make sure the arrow points toward the furnace or AC.
Many people struggle with which direction to install their air filter. To help remember, consider taking a 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 inquire about this is during a regular furnace maintenance call.
Changing Your Furnace's Air Filter
Changing the filter on your furnace or air conditioning system is a simple process. Here is a step-by-step rundown of how to take out a dirty air filter and swap 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 located in the furnace or in the air return vent. Make a mental note or write down which direction the arrow points on the filter, because you’ll want the arrow on the new filter to point the same way.
- Slide out the old filter: Be diligent not to knock out any dust or particles.
- Document the date: Write down the date you replaced the filter 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 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 place.
- Turn on your furnace: Once the new filter is safely in place, 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 cease working or reduce its lifespan. Changing your furnace or AC filter is one of the simplest things you can do to keep your system working correctly.