THE OPPORTUNITY

PS&S was asked to perform design services to replace the HVAC system at the existing Communications High School located in Wall Township, New Jersey. Services included architecture, MEP, structural, and cost estimating services.

THE CHALLENGE

PS&S previously performed an evaluation for the existing HVAC system in the building. The HVAC system was serviced by a water source heat pump system to heat and cool the building. The system utilizes condenser water, which is connected through a piping system to a cooling tower for cooling water and the boiler for heating water. Heat pumps and a cooling tower are approximately twenty years old and at the end of their expected useful life according to ASHRAE’s Equipment Life Expectancy.

The cooling tower has been experiencing significant maintenance problems and is showing signs of corrosion in the fluid as reported by the service vendor for the cooling tower; therefore, the cooling tower is not functioning at full capacity. PS&S was charged with selecting a replacement HVAC system that would be cost-effective to install, operate, and maintain. The District preferred the new system not rely on one major piece of equipment to operate, so the risk did not exist for the entire system to be down in the event of a cooling tower failure. The proposed system was intended to work with existing infrastructure while minimizing major changes to the building, if possible.

THE PS&S SOLUTION

PS&S considered multiple system options early in the evaluation. Four system options were considered including central air handlers, expanded chilled water for replacing and upgrading the existing HVAC system, replacing the existing condenser water heat pumps with packaged rooftop air handlers, and replacing the condenser water heat pumps with variable refrigerant flow (VRF) systems.

The water heat pumps with variable refrigerant flow (VRF) systems was selected and included replacing condenser water heat pumps with refrigerant, split-type heat pumps, and replacing undersized split type heat pumps and ERVs with a new VRF system, including dedicated outdoor air systems (DOAS). All proposed units would handle the current heating and cooling loads based on current use functions within the building. Some units were resized to meet current code and changes in use within the building. Construction was simplified into two phases to meet budget constraints and occupancy requirements of the District.

The project budget was estimated to be $4.0 Mil. The bids were competitive and allowed the base bid and 5 alternate bid items to be awarded for a total cost of $3.56 Mil including boiler, Kitchen Make-Up Air and Exhaust Units, and the building management control system for the building. The project was bid during the COVID-19 pandemic which required modifications to the bid opening process and procedures during bidding administration. The PS&S teams’ efforts and attention to detail allowed the project to be awarded within the schedule constraints