Choosing 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 vital part in keeping its system working safely, efficiently and for a long time.
A clogged furnace filter loses its effectiveness, enabling potentially harmful particles to flow through your home. It also restricts airflow, which can damage your furnace and reduce its life span.
Making certain your furnace uses a clean filter that is ideal for your needs is not merely about keeping your furnace running efficiently. It’s also about delivering excellent indoor air quality for your home.
The health of your family is important to the heating and cooling pros at May's Heating & Air. We've long been dedicated to enhancing indoor air quality in Frederick. Here, we’ve answered frequent questions about HVAC filters, including that very 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 periodically. Soiled filters cause the system to worker harder than it should because it takes more energy to pull air through the plugged-up filter.
Officials recommend inspecting your furnace filter every 30 days and replacing it if it’s dirty. You’ll know if your filter needs changing because it will filled with dirt or dust. Homeowners who have dogs and cats will likely have to replace their furnace air filter more often, because a quality 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 normally installed in the return air duct or blower compartment before the return air reaches the furnace. This is so air being pulled 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 within a slot, frame or cabinet for easy access and replacement. Always refer to your furnace's owner manual for facts about filter location of your furnace.
Is My Furnace Filter Just a Type of Air Filter?
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 might refer to them differently based on the current season— hot or cold—they are all filters that clean the air in your HVAC system.
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 find your old furnace filter and figure out when it should be replaced, it’s time to pick a replacement. That means deciding on the level of filtration that you need. One way to do that is by selecting an appropriate MERV rating for your needs.
MERV stands 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 higher numbers indicating a greater ability to filter small particles.
Experts say a filter with a MERV rating between 8 and 13 offers an appropriate balance between having good indoor air quality without overly 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
Positioning an air filter in a furnace or air conditioner the proper way is crucial for the efficient operation of the system. Air filters have a particular direction, indicated by an arrow located 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 not sure about the airflow direction, try to remember that air always moves from the return duct to the heat or cooling source. Therefore, make sure the arrow points toward the furnace or air conditioning unit.
Many people struggle with which direction to point an air filter. To help remember, consider taking a picture with your mobile phone after the filter has been accurately 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 ask about this is during a routine furnace maintenance call.
How to Change a Furnace Air Filter
Replacing the filter on your furnace or air conditioner is an easy process. Here is a step-by-step list of how to take out a dirty air filter and swap it for a new one:
- Turn off your furnace: Be sure to switch off your furnace before starting the process.
- Look for 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 in the same direction.
- Remove the old filter: Be careful not to knock out any dust or particles.
- Document 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 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 correctly and close any latches or clips that lock it in place.
- Turn on your furnace: Once the new filter is completely secured, you can turn your furnace back on.
Will a Dirty Air Filter Damage My Furnace?
The simple 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 running effectively.