METRIC DESIGN GUIDE
This directory lists domestic manufacturers of commercial building products in one of the
Manufacturers who make products that will not change size during metric conversion, but
have developed product literature with metric dimensions in it.
Manufacturers who currently manufacture or can manufacture round metric product sizes.
Each section will identify if the product being discussed is a converted odd dimension product
or a round metric product size. All building products in this directory are made in the United
States. Firms interested in being included in this directory may do so by contacting the
Construction Metrication Council of the National Institute of Building Sciences, 1201 L
Street, NW., Washington, DC 20005.
Air Diffusers and Grilles
Lay-in air distribution grilles and diffusers use round metric sizes. Those that are wall
mounted or ceiling mounted in drywall or cut in tile may use converted dimensions. Many
companies making metric sizes simply modify their existing product.
The actual width of a nominal 24- by 24-inch (610 by 610 mm) diffuser is usually about
23-3/4 inch (604 mm).
To produce the same product for a nominal 600 by 600 grid, each edge must be slightly
shorter, or about 590 mm (23-1/4 inch).
The following manufacturers can make round metric sizes for layin type applications.
Acutherm, Emeryville, CA, a manufacturer of variable air volume air distribution devices,
can manufacture its products in round metric sizes (Jim Kline, 510-428-1064).
Aireguide, Hialeah, FL, a large manufacturer of air distribution products, can make 80 to
90 percent of its products in round metric sizes (Daryl Gray, 305-888-1631).