Selecting the ideal 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 operating safely, efficiently and for a long time.
A clogged furnace filter loses its effectiveness, permitting potentially harmful particles to flow through your home. It also slows airflow, which can damage your furnace and decrease its life span.
Ensuring your furnace uses a clean filter that is appropriate for your needs is not merely about keeping your furnace running efficiently. It’s also about providing good indoor air quality for your residence.
The quality of the air your family breathes is important to the HVAC specialists at Rescue Heating & Air. We've long worked with an eye on improving indoor air quality in Alice. 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
Experts stress it's 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 more energy to move air through the plugged-up filter.
Officials advise examining your furnace filter every month 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. Homeowners who have pets will probably 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 commonly found in the return air duct or blower compartment before the return air reaches the furnace. This is so air entering the system is filtered before it moves through the furnace components and is heated.
Depending on the furnace model, the filter may be positioned on the right, left, bottom or in some cases, inside the furnace. It's usually housed inside of a slot, frame or cabinet for simple access and replacement. Always refer to your furnace's owner manual for facts about filter location of your particular brand and model of furnace.
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 conditioning filter are essentially the same thing. While people may call them different things based on the current season— hot or cold—they are all filters that clean the air in your residence.
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 flowing through your home is clean and safe.
What Is the MERV Rating System and What Rating Is Best for Me?
Once you track down your old furnace filter and decide when it should be substituted for a clean one, it’s time to pick a replacement. That means picking the level of filtration that you need. One way to do that is by choosing an appropriate MERV rating for your needs.
MERV is an abbreviation for Minimum Efficiency Reporting Values. The MERV rating measures the effectiveness of air filters at trapping airborne molecules. The rating scale ranges from 1 to 20, with greater numbers indicating enhanced capabilities to filter smaller particles.
Experts say a filter with a MERV rating between 8 and 13 offers an appropriate balance between having good indoor air quality without needlessly restricting airflow. However, people with specific health conditions may need to use a filter with a higher MERV rating.
Where to Insert the Air Filter in a Furnace or Air Conditioning System
Positioning an air filter in a furnace or air conditioner properly is crucial for the efficient operation of the unit. Air filters have a certain direction, indicated by an arrow written on the side of the filter frame. The filter should be installed with this arrow pointing toward the furnace or AC, 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 towards the heat or cooling source. Therefore, make sure the arrow points at the furnace or AC.
Many people are confused by which direction to point their air filter. To help remember, consider taking a quick 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 go. A perfect time to do this is during a regular furnace maintenance call.
How to Change a Furnace 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 remove 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.
- Look for 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 clean filter to point in the same direction.
- Take out the old filter: Be careful not to knock out any dust or dirt.
- Document the date: Write down the date you replaced the filter on the new filter's frame. This will help you keep track of when it's time for the next change.
- 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 old filter you are replacing.
- Secure the filter: Make sure the new filter fits correctly and close any latches or clips that hold 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 short answer is, yes, a dirty air filter can cause a furnace to quit working or reduce its lifespan. Changing your furnace or AC filter is one of the best things you can do to keep your system working effectively.