A St. Louis high school has a new, green HVAC system, thanks in part to a local contractor.

St. Louis-based mechanical contractor Wiegmann Associates has completed its part of a $13 million renovation project at Parkway North High School. Working under general contractor ICS Construction Services, Wiegmann demolished and installed a new energy-efficient HVAC system, recommissioning an existing chiller and boiler and installing two new chillers. The company also put in two new chillers and a rooftop unit with an energy recovery wheel.

The project also required modifying the existing ductwork, putting sound attenuators in them and installing variable air volume boxes.

Much of the work took place while school was in session, the company said.