Evan C. Walden, P.E., Principal, Senior Mechanical Engineer has over 30 years experience in the design and installation of mechanical systems for consulting engineering firms and for industry. Mr. Walden has expert competence in the fields of indoor air quality and HVAC; fume hood, and materials handling systems including dust collection. Mr. Walden has published several respected industry papers, which explore the issues of indoor air quality and ventilation for safe occupancy. Mr. Walden serves as national chair for an ASHRAE technical committee and is past president of the ASHRAE Northeast chapter.

John S. Edwards, P.E., LEED® AP, Principal, Senior Mechanical Engineer has over 27 years experience with consulting engineering firms & 2 top 20 Architecture/Engineering firms, with design responsibilities on projects budgeted up to $500 M. Mr. Edwards' experience is in HVAC system design for commercial, industrial & institutional project. He is a specialist in the design and troubleshooting of microprocessor-based temperature controls, and in the design of central energy plant and distribution systems.