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 Curtains COILS: IFB, VIFB and MV Integral Face and Bypass Coils MAKE-UP AIR: SAS Steadyair® Make-Up Air Units; FAS Fresh Air Supply Units, and WDF Direct-Fired Gas Heaters: UNIT HEATERS HU, HCF, and HCR Unit Heaters; HMS, HMG High Mounting Series Unit Heaters; GA Gas Assemblies; and HLC High Level Circulators Wing HS FAS High Static Fresh Air Supply Units Description The High Static Fresh Air Supply (HS FAS) provides a versatile heating system for applications requiring the ducting or filtering of make-up air. Supporting up to Merv 10 filters or 2.5 inches of ducted static pressure, the HS FAS is the perfect make-up air heater for interior rooms such as kitchens, painting, plating, welding, etching, and other food or chemical processing facilities.