Energy savings modelling of re-tuning energy conservation measures in large office buildings

Abstract

Today, many large commercial buildings use building automation systems to manage a wide range of equipment. This paper investigates the energy savings potential of several common heating, ventilation, and air conditioning (HVAC) system re-tuning measures on a typical large office building using the EnergyPlus software. Individual re-tuning measures simulated include automatic schedule adjustments, damper minimum flow adjustments, thermostat adjustments, as well as dynamic resets to static pressure, supply-air temperature, condenser chilled- and hot-water temperatures, and chilled and hot water differential pressure set points. All individual measures and combinations were simulated in 16 locations representative of different climates in the USA. Many of the demand-side individual measures were capable of reducing annual HVAC energy consumption by over 20% in most cities. Supply-side measures affecting HVAC plant conditions were only modestly successful (less than 5% annual HVAC energy savings). Some of the combinations revealed between 35% and 75% HVAC energy savings.

Keywords:

• re-tuning
• HVAC
• EnergyPlus
• modelling

Acknowledgements

The authors would like to thank Ron Underhill for providing the technical review, Sue Arey for editorial support, and Lorena Ruiz for help in preparing this document.

Additional information

Funding

The authors would like to acknowledge the Office of the Washington State Attorney General and the Buildings Technologies Office of the US Department of Energy Office of Energy Efficiency and Renewable Energy for supporting the research and development effort.