Center for the Built Environment

ASHRAE Guideline 36 defines standardized high-performance control sequences for heating, ventilation, and air conditioning (HVAC) systems, yet limited field evidence exists on its plant-level applications. In this project, the team implemented Guideline 36 supply water temperature reset sequences for two hot water plants and a chilled water plant using a layered architecture of supervisory control, Building Automation and Control Networks (BACnet) communication, Control Description Language (CDL) based programming developed by ASHRAE Standard 231p, and Brick ontology to ensure scalability and interoperability. Measurement and verification (M&V) with weather normalization showed savings of 3.28 kBTU/ft²-year (10.38 kWh/m2-year)(7.5%) and 10.15 kBTU/ft²-year(32 kWh/m2-year) (11.5%) for the hot water plants, and 6.61 kWh/m2 (2,097 BTU/ft2) (14.6%) for the chilled water plant, translating to cost reductions of $0.095/ft2-year ($1.02/m2-year), $0.17/ft2-year ($1.82/m2-year), and $0.12/ft2 ($1.29/m2), respectively. These results provide empirical evidence of Guideline 36’s effectiveness in plant applications and highlight its potential for broader adoption. Additionally, retro-commissioning efforts in one building reduced chilled water energy use by 16%, demonstrating the importance of addressing existing operational inefficiencies to fully realize the benefits of advanced control strategies.