After numerous water leaks, compressor failures and damper control problems, it was time for South High Community School in Worcester, MA to replace the 30 year old HVAC rooftop units. Not only had the units outlasted their expected mechanical life, but the ability to deliver fresh outdoor air and maintain comfortable heating and cooling conditions became increasingly difficult and expensive. To specify a state-ofthe- art replacement HVAC rooftop system, the energy and environmentally conscious school district enlisted the services of a local engineering firm.