Air filters are designed with arrows printed on the sides to indicate the direction in which air should flow through the system. Generally, this is away from the supply ducts and towards the blower. If the filter is on the ceiling, the arrow should face upwards, and if it is on the wall, it should point towards the wall. Most air filters are designed to fit properly only when installed correctly.
Look for the arrows printed on the side of the filter that show which way it should be inserted. The arrows always point in the direction of air flow. When installing a new air filter in an AC return duct, the arrows should face inward to indicate that air is being pulled in. If there is an air return on the ceiling or wall that uses a filter, the arrow should point towards that surface.
It is important to install air filters correctly because a dirty and clogged filter will reduce efficiency and cost you extra money. In some downflow ovens, two filters may need to be placed in a V-shaped angle in the upper compartment of the fan. The filter should always be located near the fan of the intake air blower so that air passes through it and removes dirt, dust, pet dander, pollen and other particles that can damage the oven. When installing an air filter, make sure to check for arrows printed on its side and insert it in the correct direction. This will ensure that your heating and air conditioning system runs efficiently and provides clean air for your living space.