LJ Wing Who We Are LJ Wing is a manufacturer of Heating, Ventilating, and Air Conditioning (HVAC) components ideal for controlling the temperature and quality of outside air for any commercial or industrial building. Our product mix includes steam or hot water integral face and bypass coils, steam or hot water unit heaters, steam or hot water boiler combustion preheaters, steam or hot water air handling units, door heaters and air curtains, and industrial gas unit heaters. LJ Wing invented the integral face and bypass coil concept 50 years ago to protect air handler coils from freezing when handling large amounts of outside air. See our product catalog to view the full range of heating, ventilating and air conditioning components. DOOR PROTECTION: DH Door Heaters; WAC Air CurtainsCOILS: IFB, VIFB and MV Integral Face and Bypass CoilsMAKE-UP AIR: SAS Steadyair Make-Up Air Units; FAS Fresh Air Supply Units, and WDF Direct-Fired GasHeaters: UNIT HEATERSHU, HCF, and HCR Unit Heaters; HMS, HMG High Mounting Series Unit Heaters; GA Gas Assemblies; and HLC High Level CirculatorsWing HS FAS High Static Fresh Air Supply Units DescriptionThe High Static Fresh Air Supply (HS FAS)provides a versatile heating system forapplications requiring the ducting or filtering ofmake-up air. Supporting up to Merv 10 filters or2.5 inches of ducted static pressure, the HSFAS is the perfect make-up air heater forinterior rooms such as kitchens, painting, plating, welding, etching, and other food orchemical processing facilities.