If a building is minimally occupied but its energy use doesn’t go down much, why might that be? Technicians can check these areas:

Setpoints. Is the building using setbacks for unoccupied operating hours? Check the temperature setpoints and schedules, both occupied and unoccupied.

Equipment loads. Is equipment plugged in that should be shutting down or going into sleep mode that isn’t? Check copiers, printers, audio-visual systems, televisions, and individual plug-in heaters. It is surprising the amount of power these systems can draw when not properly shut down. They also add to the building’s heat load.

Lighting. Lighting accounts for a significant portion of a building’s energy use. Are the lights turned off in areas that are not occupied? Check lighting during unoccupied hours.

Economizer dampers. Are they opening and closing correctly? An economizer damper that is stuck open lets in more outside air than the system is calling for and can overburden the heating and cooling system, as well as waste energy by cooling more outside air than needed.

Simultaneous heating and cooling. Are HVAC systems calling for both heating and cooling when they should not be? This situation can happen for a number of reasons. A valve could be stuck, a sensor could be mis-reporting, or a damper could be broken.

System controls. One lesson for managers over the last year and a half is that control systems can serve a significant role in planning and preparedness. More advanced systems can help technicians dial back system setpoints and schedules so that the impact of scaling back operations is part of a plan, not a reaction to an event.

**excerpt from an article in FDM Magazine