Our Service Capabilities NAICS 541330 Engineering Services. NAICS 541690 Other Scientific and Technical Consulting Services. DUNS: 079188211 Cage Code: 70SN6 MECHANICAL AND HVAC ENGINEERING SERVICES: Piping and HVAC design for new facilities and energy efficiency upgrades. Mechanical Inspection Services covering piping, HVAC, fire protection and life safety systems. Qualified Professional Engineer Design and Mechanical Code Compliance Reviews. Value Engineering to identify opportunities for improved functionality and design cost effectiveness. High-Performance Healthcare HVAC Systems design. Hazardous waste facilities. Schools/Education facilities Mechanical and HVAC design. Power Generating Facilities Mechanical Systems design.