eggcrate return air grille
This common style of floor air return was popular during the heyday of gravity style coal fired heating system. Because of the lack of a fan heated air would rise or fall through the heat registers via the process of convection. As a result duct openings had to be much larger than the sizes we are typically familiar with today. When a duct opening is located on the floor it becomes problematic to provide a vent cover that is strong enough to support much weight as the duct opening size gets larger. One factor contributing to strength of the grille is the type of wood. Oak is generally a good choice, being a strong wood and one that works with a wood floor of similar material. Certainly that is much better than a soft wood like pine. Also, the quality of joinery is important. Eggcrate grid floor vents from back in the day often had very crude joints and did not even have glue in the joint to help out! Our joinery is on a complete other level and is made with highly calibrated machinery as well as glue joints. It is sufficient to support weight up to twelve inches. For dimensions above that we offer attached welded steel support structures (shown above), which extend the weight capacity to previously unknown heights. Furthermore, we offer surface mount as well as flush mount choices
wood air return duct openings
If you have not already done so, it is a good idea to clean out the duct opening. Masking off the area and giving the opening a light coat of flat black spray paint will go a long way to projecting a professional appearance as everything in the opening will recede into shadow.