Spectrum

Opportunity

Status

Estimated Start:

Total Annual Savings

Project Cost:

Project Payback:  

Description

Connected Commissioning

Not Started

FY 2020

$70,800

$270,000

3.8

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 using the Schneider BAS 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.

Recommendation: 

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 Main Air Handler & Hot Deck Air Handlers (AHUs) - Hot Deck AHUs are enabled whenever any zones are requesting heat, including zones that are not connected to the heating AHUs. Reprogram units so that only the zones connected to heating are able to enable the AHU.

• Heating & Cooling Setbacks - Install occupancy sensors for HVAC control; program to allow the minimum flow setpoint to be 0 CFM in the zone when unoccupied during scheduled hours.

• Program Air Handler/Rooftop Unit (AHU/RTU) Static Pressure Reset - Static pressure setpoint resets are not configured for variable volume AHU systems. Program AHU supply air static pressure reset to modulate the supply air static pressure setpoint in order to maintain the maximum (critical) zone supply air damper position at an adjustable setpoint. For example, if static pressure setpoint is fixed at 1.5" water column (W.C.), reset between 0.2 - 1.75” W.C. based on VAV zone voting as referenced in ASHRAE Guideline 36.

• Boiler Lockout - Program boiler lockout based on outside air temperature (e.g. outside air temperature above 80°F) or lack of calls from the hot deck AHUs. If boiler lockout is dependent on outside air temperature, ensure program includes wide hysteresis (10°F typ.) to prevent constant on/off cycling.

• Program Boiler System Heating Hot Water (HHW) Reset - 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.

• Program Chilled Water (CHW) Setpoint Reset - Program reset of chiller supply temperature setpoint, e.g. from 42-48°F based on air handler (AHU) chilled water valve position feedback (max or average) or when outside air temperature varies from 70 - 90°F.

• Chilled Water (CHW) Variable Speed Pumps & Loop Differential Pressure (DP) Reset - Program the system differential pressure setpoint to modulate pump speed and reset the CHW setpoint based on valve position of the air handlers.

• Program Condenser Water (CDW) Reset - Program cooling tower fans to modulate fan speed in order to maintain cooling tower leaving chilled water (CW) temperature setpoint and reset CDW temperature setpoint between 60 - 75°F. For example, if cooling tower fan speed is above 90%, increase CDW setpoint. If cooling tower fan speed is below 60%, reduce CDW setpoint.

• 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.