48LC Weather Expert is an expert cooling compressor with enhanced feature SAV (Carrier Staged Air Volume), which allows an extra comfort, humidity control and saves lot of energy. It is a dynamic commercial rooftop so far produced which can perform multi-stage heating or even in single stage. As it makes use of Comfort Link controls and a belt drive with a variable frequency, the system is optimal for individual zone air volume competence. It has other features like Ultra-high efficiency, is a single package rooftop and has Electric Cooling and Gas Heating units. Units are charged and wired in advance with Puron HFC refrigerant, which is environmentally sound. Maintenance features includes its innovativeness, no-strip screw feature on unit access panels and easy starting. It has two-inch disposable air filters and a non-tool filter access door. It is available either in two-stage, weighing 3 to 5 tons or in three-stage, weighing 6 to 23 tons, both having cooling capacity control.