SCHOFIELD, WI — Greenheck, a manufacturer of commercial and industrial air movement and control equipment, is one of the first manufacturers to offer fire, smoke, and combination fire/smoke damper products in compliance with new UL 555 and 555S testing requirements.

In fact, many of the manufacturer’s fire/smoke dampers met the new requirements in April 2001 — a year ahead of the July 2002 deadline.

The new UL standards are designed to increase damper reliability and ensure safer operation during a fire. To comply with the revised standards, smoke dampers must pass new heated air operation tests. New requirements mandate that dampers operate against a minimum airflow of 2,000 fpm and 4 in. wg pressure. Final ratings incorporate a safety factor of 400 fpm on airflow and 0.5 in. wg on pressure. All operation and leakage ratings now require testing with airflow in both directions through a damper. Cycle test requirements have been increased from 5,000 to 20,000 cycles. Similar requirements apply for fire damper closure tests.