Experts In Mechanical Contracting KEEPING YOU COOL' SINCE 1975! That's over 45 years! Environmental Systems Inc., has evolved as a leader in cutting edge technology, while keeping pace with the ever changing HVAC and energy management environments. We keep in mind, the basic goals of customer service and satisfaction. This formula has enabled our company to grow steadily since its founding in 1975. ESI has been a consistent force in the plan and spec market, as well as proving our capabilities in design / build-negotiated projects. ESI handles commercial projects, both large and small, with equal care and commitment to excellence.