Picking out 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 crucial role in keeping its system running safely, efficiently and for a long time.

A clogged furnace filter loses its effectiveness, allowing potentially harmful particles to move through your home. It also slows airflow, which can damage your furnace and shorten its life span.

Ensuring your furnace uses a clean filter that is suitable for your needs is not merely about keeping your furnace running efficiently. It’s also about delivering excellent indoor air quality for your household.

Your health is important to the HVAC specialists at ACE Solutions. We've long been dedicated to bettering indoor air quality in Hasbrouck Heights. Here, we’ve answered common questions about HVAC filters, including that especially 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

Experts stress it's 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 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 your filter needs changing because it will coated with dirt or dust. People who have pets will probably want to replace their furnace air filter more often, because a good 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 usually installed in the return air duct or blower compartment before the return air gets to the furnace. This makes sure air entering the system is filtered before it goes through the furnace components and is heated.

Depending on the type of furnace, the filter may be found on the right, left, bottom or in some cases, within 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 facts about filter location of the furnace in your home.

Is a Furnace Filter the Same as an Air Filter?

The easy answer is, yes. In HVAC, a furnace filter and an air filter or AC filter are effectively 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 get rid of dust, allergens, bacteria and other contaminants from the air that is drawn into the furnace and air conditioning system, making certain the air circulating throughout your home is clean and safe.

What Are MERV Ratings and What Rating Is Best for Me?

Once you locate your old furnace filter and figure out when it should be changed, it’s time to pick a replacement. That means determining the level of filtration that you need. One approach to this is by picking 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 particles. The rating scale ranges from 1 to 20, with greater numbers indicating a greater ability to filter tinier particles.

Experts say a filter with a MERV rating between 8 and 13 offers an appropriate balance between having healthy indoor air quality without unnecessarily restricting airflow. However, people with some health conditions could need a a higher MERV rating.

How to Place the Air Filter in a Furnace or Air Conditioner

Positioning an air filter in a furnace or air conditioner correctly is necessary for the efficient operation of the heating or cooling system. Air filters have a particular direction, indicated by an arrow located on the side of the filter frame. The filter should be put in with this arrow pointing at the furnace or air conditioning unit, which is the direction of the airflow. If you're doubtful about the airflow direction, try to remember that air always moves from the return duct and then to 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 quick picture with your cell phone after the filter has been correctly 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 great time to ask about this is during a regular furnace maintenance visit.

Changing Your Furnace's Air Filter

Replacing 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 exchange it for a new one:

  1. Turn off your furnace: Make a point to switch off your furnace before starting up the process.
  2. Locate the furnace filter: Typically, the filter is found 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 in the same direction.
  3. Take out the old filter: Be careful not to knock out any dust or particles.
  4. 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 another replacement.
  5. 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.
  6. Secure the filter: Make sure the new filter fits nicely and close any latches or clips that secure it in the unit.
  7. Turn on your furnace: Once the new filter is completely secured, you can turn your furnace back on.

Can a Dirty Air Filter Cause a Furnace Not to Work?

The simple answer is, yes, a dirty air filter can cause a furnace to cease working or reduce its lifespan. Changing your furnace or air conditioner filter is one of the simplest things you can do to keep your system operating efficiently.