Not every furnace filter has an arrow stamped on its side, but when you do see it, it indicates which direction the filter has to face. It always points to the direction of the furnace’s air handler or blower compartment. Even though the filter may look the same on each side, there are differences that affect how it lets air through it and into your HVAC system.
As a homeowner, you may not be familiar with the intricate workings of your furnace, but it does pay to have a basic knowledge about certain important components including the furnace filter. Understanding the role your furnace filter plays in your home heating can help save you money on repairs, heating costs and improve your indoor air quality.