Choosing the proper 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.
A clogged 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 just about keeping your furnace working efficiently. It’s also about providing good indoor air quality for your home.
Your health is important to the HVAC pros at Point Heating & Cooling. We've long worked with an eye on improving indoor air quality in Plover. 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?
When Should I Replace My Furnace Air Filter?
It is critical to replace dirty air filters in a furnace or air conditioner periodically. Dirt-clogged filters cause the system to worker harder than it should because it takes extra effort to force air through the plugged-up filter.
Officials recommend checking your furnace filter monthly and replacing it if it’s dirty. You’ll know if it is dirty because it will filled with dirt or dust. Those who have pets that shed will probably need to replace their furnace air filter more often, because an effective 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 found in the return air duct or blower compartment before the return air goes back into the furnace. This makes sure air flowing into the system is filtered before it passes 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, within the furnace. It's usually housed in 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 effectively the same. While they might be called different things based on the current season— hot or cold—they are all filters that clean the air in your home.
They each remove dust, allergens, bacteria and other airborne debris from the air that is drawn into the furnace and air conditioning system, making sure the air circulating throughout your home is clean and safe.
What Is a MERV Rating and What MERV Rating Do I Need?
Once you find your old furnace filter and decide when it should be changed, it’s time to pick a replacement. That means determining the level of filtration that you need. One method to do this is by selecting 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 particles. The rating scale ranges from 1 to 20, with bigger numbers indicating the power to filter smaller particles.
Experts say a filter with a MERV rating between 8 and 13 offers an ideal balance between having healthy indoor air quality without overly restricting airflow. However, people with some health conditions might need to purchase a filters 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 necessary for the efficient operation of the heating or cooling system. Air filters are designed to be installed in a specific direction, indicated by an arrow printed on the side of the filter frame. The filter should be put in with this arrow pointing toward 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 certain the arrow points toward the furnace or air conditioning unit.
Many people have difficulty remembering which direction to point their air filter. To help remember, consider snapping a quick photo with your cellular 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 handy time to do this is during a routine furnace maintenance appointment.
Changing Your Furnace's Air Filter
Changing the filter on your furnace or AC is a quick and easy process. Here is a step-by-step list 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 beginning the process.
- Find the furnace filter: Typically, the filter is positioned inside 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 similarly.
- Slide out 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 your family keep track of when it's time for you to change it again.
- Put 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 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 clean filter is properly secured, you can turn your furnace back on.
Will a Dirty Air Filter Cause Problems for a Furnace?
The short answer is, yes, a dirty air filter can cause a furnace to quit working or limit its lifespan. Changing your furnace or air conditioning filter is one of the best things you can do to keep your system running efficiently.