House Sealers by Kate O'Brien Imports help tighten U.S. houses. Resource Conservation Technology sells several imported products for use in energy-efficient construction. Tenoarm is an 8-mil-thick air/vapor barrier from Sweden. It is transparent like polyethylene, but unlike poly is very durable. Tenoarm comes in four widths designed to fit ceilings, walls, and floors. The company also sells Teno Sealant to be used with the film EPDM building gaskets for various applications, and air/vapor barrier boxes for use with both metal and plastic receptacles. For more information about these products, contact Resource Conservation Technology, Inc., 2633 N. Calvert St., Baltimore, MD 21218; 301/366-1146. Aluminum Siding Revisited Wall Blanket Reflective insulation uses aluminum foil to stop heat loss and radiate heat Foil Ray is a ¼-inch-thick double polyethylene bubble