Tjernlund Products has expanded its product line with destratification ceiling fans, which are designed to recirculate trapped air in high-ceiling areas. The compact high-velocity fans operate on 30 watts and can reduce the usual temperature differential of 20 degrees or more between ceiling and floor levels by at least 50 percent, company officials say. The D-Strat fans do not have visual moving blades, offering a quieter environment ideal for office areas. Instead, the discharge velocity of 2,000 feet per minute moves air efficiently in a defined column to the floor level, officials say. The fans are available in white or black finishes to complement ceiling color and have an integral fire safety switch.