Tamarack Technologies has answered another key HVAC need, even before many designers and builders knew they had one. The problem, which is well documented, occurs in forced-air heating and cooling systems when the air flow between a supply register and return grille is choked off by a closed door. One solution is to run a return duct to every room that has both a supply grille and a door. This is effective, but expensive. Another solution is a transfer grille that allows air to flow through the partition wall from one room to another. The typical situation allows light and sound to pass through, which compromises privacy.

Tamarack's version of the transfer grille, called Zenon, allows air flow but reduces sound transmission and blocks almost all light. Two pieces of black foam inside the Zenon serve as baffles to block light and greatly reduce sound transmission. The Z-pattern created by the baffles reduces air flow slightly.

The device comes in two sizes: 4 in. x 12 in. and 4 in. x 24 in. Both models will accommodate wall thicknesses from 3.5 in. to 6.5 in. Zenon has two metal sleeves that slide into the wall from opposite sides. Metal grilles mount to flanges on the sleeves.

At the same pressure, a 1/2-inch gap at the bottom of a door allows 136 CFM while the 12 in. Zenon allows 109 CFM. Tests showed a sound level of 46 dBa for the Zenon and 61 dBa for an unrestricted opening, which is a significant reduction. Retail price for the Zenon 12 is $29.95 and the Zenon 24 is $34.95. Quantity discounts are available.

Contact: Tamarack Technologies