Picking out the correct 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 vital part in keeping its system operating safely, efficiently and for a long time.
An overused furnace filter loses its effectiveness, allowing potentially harmful particles to flow through your home. It also restricts airflow, which can damage your furnace and decrease its life span.
Ensuring your furnace uses a clean filter that is suitable for your needs is not merely about keeping your furnace operating efficiently. It’s also about providing excellent indoor air quality for your household.
The health of your family is important to the HVAC pros at SKC AC LLC. We've long worked with an eye on improving indoor air quality in Big Spring. Here, we’ve answered frequent 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's critical to replace dirty air filters in a furnace or air conditioner regularly. Dirt-clogged filters cause the system to worker harder than it should because it takes more energy to pull air through the plugged-up filter.
Officials suggest inspecting your furnace filter every month 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. Homeowners who have pets will very likely 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 commonly located in the return air duct or blower compartment before the return air reaches the furnace. This ensures air flowing into the system is filtered before it goes through the furnace components and is heated.
Depending on the type of furnace, the filter may be located on the right, left, bottom or in some cases, on the inside of the furnace. It's typically housed inside of a slot, frame or cabinet for simple access and replacement. Always refer to your furnace's owner manual for important information about filter location of the furnace in your home.
Is My Furnace Filter Just a Type of Air Filter?
The easy answer is, yes. In HVAC, a furnace filter and an air filter or air conditioner filter are basically the same. While people may call them different things based on the current season— warm or chilly months—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 circulating throughout your home is clean and safe.
What Is a MERV Rating and What Rating Is Best for Me?
Once you track down your old furnace filter and decide when it should be replaced, it’s time to choose a replacement. That means determining the level of filtration that you need. One way to do that is by selecting 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 molecules. The rating scale ranges from 1 to 20, with bigger numbers indicating a greater ability to filter smaller particles.
Experts say a filter with a MERV rating between 8 and 13 offers a good balance between having healthy indoor air quality without needlessly restricting airflow. However, people with specific health conditions might need to use a filter with a higher MERV rating.
How to Place the Air Filter in a Furnace or Air Conditioning System
Installing an air filter in a furnace or air conditioner correctly is important for the efficient operation of the unit. Air filters are designed to be installed in a particular 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 at 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 in the direction of the furnace or air conditioning unit.
Many people have difficulty remembering which direction to face an air filter. To help remember, consider taking a picture with your mobile 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 be installed. A great time to ask about this is during a routine furnace maintenance appointment.
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: Make a point to shut off your furnace before beginning the process.
- Find the furnace filter: Typically, the filter is positioned 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 clean filter to point similarly.
- Slide out the old filter: Be diligent not to knock out any dust or particles.
- Note 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 in the direction of 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 nicely and close any latches or clips that secure it in the unit.
- Turn on your furnace: Once the clean filter is completely secured, you can turn your furnace back on.
Will a Dirty Air Filter Cause a Furnace Not to Work?
The shortest answer is, yes, a dirty air filter can cause a furnace to stop working or decrease its lifespan. Changing your furnace or air conditioner filter is one of the best things you can do to keep your system operating efficiently.