Maximizing Energy Efficiency During Unplanned Vacancies

An Energy Saving Checklist

Disclaimer: During the COVID-19 pandemic, please refer to appropriate regulations mandated by your state before completing the following tasks in your building.


As buildings become increasingly empty with occupants switching to remote working schedules to follow social distancing during COVID-19, it is the perfect time for facility operators to implement energy saving protocols for unoccupied floors or buildings.

There are measures facility operators can take immediately to start seeing improved energy efficiency in their buildings. Assuming the building’s mechanical systems are floor-by-floor variable volume condenser water cooled air conditioning (AC) units, providing conditioned air via variable air volume (VAV) terminal units, and the entire floor is vacant, GHT Limited’s Operations and Energy Services team recommends taking the following actions:


  1. Turn off general lighting circuit breakers (CBs) while ensuring all emergency lighting is still powered.


  1. Eliminate power to receptacle CBs, except for those that serve desktop computers and IT infrastructure.


  1. Eliminate power to CBs which serve printers, copiers and similar non-critical IT equipment.


  1. If the emergency lighting is 277v, it may be possible to turn off the circuit breaker feeding power to the low voltage power transformer (because even when the transformer is not loaded, it still has electrical losses that show up as heat). NOTE: if this transformer powers IT equipment that must remain in use, then the CB must remain on.


  1. Verify that the EMS night set-back temperatures are appropriate; i.e. about 85°F during the summer months and about 58°F during the winter months.


  1. Verify that the VAV AC unit remains off unless a VAV terminal thermostat calls for night set-back (NSB) cooling or heating, or the VAV unit is being used to flush the floor with fresh air.


  1. Close window blinds to reduce the solar radiant load in the summer.


  1. Close domestic cold water and domestic hot water main valves so that fixtures do not flow.


  1. If domestic hot water is provided via insta-hot water heaters on this floor, turn off the circuit breakers providing them power.


  1. Make sure no equipment has been accidentally left in manual operation mode but is instead under the control of the building management system.


These concepts can be modified to accommodate a number of various systems. While buildings are unoccupied, it may be easier to notice building performance problems, including operating issues, aged systems, failed components, malfunctioning controls, and design issues. Contact GHT Limited if you need support to address these situations and improve MEP system performance – our Operations and Energy Services Studio can help.


Raymond Smith, CCP specializes in optimizing the performance of MEP systems in new and existing buildings. As Section Head of Commissioning and Building Operations Consulting in GHT’s Operations & Energy Services (OES) studio, he works closely with facility owners, managers, and operators to solve problems, develop strategies for operational excellence, and provide commissioning services that focus on long-term performance goals.