Features of Markel HLA122081603.024 Hazardous Location Electric Unit Heater The Markel HLA Series Hazardous Location Fan Forced Electric Unit Heater is designed for use in hazardous and explosion proof areas that require a heavy duty heater. Designed for rugged industrial applications in hazardous locations where the possibility of explosion or fire exists due to the presence of certain flammable gases, vapors, powdered metals or dust. Permanently sealed, liquid to air, finned tube heat exchanger core. Ethylene Glycol to water mixture used as a heat transfer fluid in the heater core, providing -45C. (-49F) freeze damage protection. High-performance electric motor driven fan blows air across finned tubes to effect uniform heat transfer and area heat distribution. Manual Reset capillary type limit provides high temperature regulation and is rated for 6,000 cycles of service. Stainless steel and aluminum pressure relief valve for overpressure. A back-up contactor is included for additional protection. 14 Gauge steel cabinet powder coated epoxy paint finish contains heater core, motor, and fan assembly. Narrow gap safety fan guard shields all moving parts. Adjustable louvers allow directional control of air. Copper conductor wires enclosed in rigid metal conduits carry all electrical power. Box lugs furnished for field connections within approved enclosure.