Dasco Whippany NJ 9 Whippany Rd Building D Whippany NJ 7981 is custom supply house of HVAC supplies specializing in custom sheet metal fabrication. AREAS SERVED: DASCO HVAC supply houses are located in New Jersey New York and Connecticut. BRANDS CARRIED: DASCO provides custom sheet metal as well as roof curbs adapter curbs equipment supports and grease ducts.