Return Air Grille Sizes report

A return air grille connects to the ductwork, allowing air to return to the heating and cooling system. Every return air grille is a return vent that provides a path for warm or cool air within the home to return to either your furnace or AC unit to be recharged and reused.

Return air grilles are usually fitted with filters to trap dust, pet hair, and smaller particles before they enter the ductwork; this limits the amount of cleaning required while also keeping the system running smoothly. The return vents may be in the wall or the floor depending on the system.

Return air grilles are available from catalogs, hardware stores, contractors, and plumbing manufacturers. Return air grille size is based on the hole opening in your wall or ceiling, so order accordingly. This post will introduce the common return air grille sizes.

Return Air Grille Size Guide

The return air grille of the central air conditioner is mostly square or rectangular. The main function of the return air outlet is to suck the dirty air back. If it is not cleaned frequently, black dust will accumulate in the corners on the surface of the tuyere, which is easy to distinguish. The size of the return air grille is not specified; it can be flexibly adapted according to the home decoration. Grilles are sized based on airflow and free area. The greater the airflow, the larger the grille. The indoor free area of grilles increases exponentially as the grille size increases.

There are decorative return air grilles in sizes to replace standard louvered grilles. Return air grilles are typically made in standardized size. However, many grille suppliers will provide custom-made sizes at a higher price.

Standard Return Air Grille Sizes

Return air grilles are standardized by 2" per size increase. The smallest return air grille usually starts at 4 inches by 4 inches. So, the next corresponding return air grille size includes 4×6, 6×6, 6×4, 8×6, 4×8, and so on. The largest return air grille typically stops at 48 inches by 24 inches because subsequent sizes are too large for standard applications in homes and commercial buildings. Below is a list of the common standard return air grille sizes; sizes are listed as width (horizontal) x height (vertical):

Final Words

The return air grille must be removed and cleaned regularly, in conjunction with the filter, to prevent dust from entering the heating and cooling system. To order the correct return air grille, you must remove any existing grilles from your wall and then measure the hole opening to order. Certain places like factories and production plants may call for larger grille sizes, but they are mostly custom-made. When you doubt how to pick or install, consult a professional for advice to extend the life of your control system.