Total Annual Savings:
Connected commissioning optimizes building performance, reduces operating and maintenance costs and extends equipment lifetimes. As a result of the energy audit, high priority lighting, automation/controls and heating, ventilation and air conditioning (HVAC)-related ECMs are recommended for implementation through a packaged connected commissioning project delivery. In most cases, the building automation system will be used to collect and analyze on-going performance data, identify new trends and ensure persistent savings from previously-implemented ECMs.
Perform connected commissioning with a focus on optimizing automated control sequences through programming and control device upgrades to achieve the following energy conservation measure outcomes. The connected commissioning process includes follow up investigation, controls upgrade specifications and sequences, coordination with installing contractor(s), and optimized control sequences validations. Control specifications and optimized sequences of operation will also be provided for all budgeted HVAC unit replacements.
The following measures were identified as specific opportunities to be completed as part of a connected commissioning process. These opportunities may be implemented independently or as part of a coordinated effort:
• Equipment Schedules for Air Handlers (AHUs), Boilers, & Central Plant - AHU-2, AHU-3, and AHU-4 operate continuously and can be scheduled, while the central plant and boilers operate continuously but can be interlocked with AHU equipment to run on demand. Program automatic schedules configured to occupancy requirements to reduce equipment run times. Create after-hours capability that can be used as needed to temporarily override normal schedules.
• Prevent Simultaneous Heating/Cooling Control - Economizer logic appears to be enable/disable rather than sequenced / integrated. This will lead to excessive heating energy. Re-sequence supply air temperature control programming so economizer dampers always open fully as the first stage of cooling prior to the chilled water (CHW) valve modulating open. This allows temperature control to take maximum advantage of outside air conditions prior to using chilled water for cooling.
• Program Air Handler/Rooftop Unit (AHU/RTU) Economizer Lockouts - Optimize control sequence where the economizer shall be enabled when outside air temperature is 1) lower than 50°F and 2) when outside air temperature is lower than the return/zone air temperature by 2°F. Economizer control should be disabled when outside air temperature is 1) higher than 70°F or 2) when the outside air temperature is greater than return/zone air temperature.
• Integrated Exhaust/Return Fan Control - Laboratory exhaust fan static pressure sensor location is located directly at the fan inlet on the plenum; re-install static pressure sensor further down the ductwork to allow proper control & turn-down of exhaust fans.
• Program Air Handler/Rooftop Unit (AHU/RTU) Supply Air Temperature Reset - Supply temperature setpoints are fixed; program air handler unit supply air temperature resets to modulate the supply air temperature setpoint (e.g. if supply air temperature setpoint is fixed at 55°F, reset between 55-63°F) in order to maintain total zone temperature cooling error at an adjustable setpoint. Use zone feedback to reset supply air temperature for both VAV zone and single zone units.
• Program Occupied Air Change Rate Optimization - Lab is equipped with Aircuity system for control; optimize Aircuity controls to ensure proper turn-down for all units.
• Boiler Lockout - Boilers do not lock out when there is no demand; program the boiler to be disabled when demand is non-existent.
• Program Boiler System Heating Hot Water (HHW) Reset - Boiler heating hot water (HHW) setpoint is constant; program outside air temperature reset of boiler supply temperature setpoint. For conventional boilers or boilers with 3-way valves, use 180-140°F when outside air temperature varies from 20-70°F. For condensing boilers, use 180-80°F when outside air temperature varies from 20-70°F. Alternatively, use voting or hot water value (HWV) rollup based trim and respond based resets.
• Heating Hot Water (HHW) Variable Speed Pumps & Loop Differential Pressure (DP) Reset - HHW loop differential pressure (dP) setpoint is fixed; program HHW loop differential pressure reset by modulating pump speed based on outside air temperature or difference in temperature between supply and return loop water (delta T) to reduce pumping demand.
• Program Chilled Water (CHW) Setpoint Reset - CHW temperature setpoint is fixed; program reset of chiller supply temperature setpoint, (e.g. from 42 - 48°F) when outside air temperature varies from 70 - 90°F.
• Chiller Lockout - Chillers operate continuously; program chiller control to be locked out based on demand from AHUs.
• Program Condenser Water (CDW) Reset - Condenser water setpoint is dependent on chiller loading; reprogram condenser water setpoint to reset based on dewpoint or cooling tower fan speed. This will lead to more optimal operations.
• Auto Shutdown of PCs - Utilize software that allows PCs to be shut down when not in use.
• Demand Response Sequence - Program sequences to allow non-critical loads such as common area lighting, fountains, displays, etc. to remain OFF during peak hours. Use any available load-shifting technology to delay energy use until after the peak period.