This client had $310,00.00 in expenses for a building management system with no energy reduction. We rewrote the AHU sequences in the client energy model and optimized their controls. This energy retrofit resulted in $89,000.00 in annual savings for the client with a 4.9ROI.
Scope of WorkECM-1. Install VFDs for AHU fans and pumps at chiller plant
- All AHUs (10 hp each, Qty 24)
- Chilled water pumps (25 hp each, Qty 2)
- Condenser water pumps (20 hp each, Qty 2)
- Hot water pumps (20 hp each, Qty 2)
ECM-2. Control Upgrade
AHUs serving the retail space (Qty 14)
- Remove existing pneumatic controls•Install and program new BACNET IP controllers
- Install new temperature sensors•Install new space temperature sensor / thermostats
- Install new EP transducers to control existing pneumatic valves
- Install new IP connections (network switches and cables)
AHUs serving the Tower (Qty 10)
- Remove existing Carrier controllers
- Install and program new BACNET IP controllers
- Reuse existing temperature sensors and pneumatic valves
- Install new IP connections (network switches and cables)
Chiller and boiler plant
- Install and program new BACNET IP controllers with adequate IO modules
- The new controllers will control all major equipment including chillers, boilers, pumps, cooling towers, valves, etc.
- Install new sensors where necessary and re-use existing sensors
- Install new IP connections (network switches and cables)
Miscellaneous
- Install new CO2 sensors in representative locations to monitor building ventilation
- Install a new building pressure sensor to monitor building pressurization
- Install an outside air temperature / humidity combo sensor
Building Automation System
- Install a new cloud-based BAS based on latest Niagara-platform
- Install supervisor license on a new server PC
- Integrate all IP devices into the supervisor
- Create graphics for all major HVAC systems and equipment
- Setup schedules, alarms and trends
- Alarm notifications can be sent through emails or text messages to designated personnel with manageable escalation schemes (internet required).
- Weather data (and forecast) can be made directly available to BAS through internet from selected weather station(s) to help BAS and building operators making operational decisions
ECM-3. HVAC optimization
Central Utility Plant
- Optimize and reset chilled/hot water loop differential pressure (DP) set points based on building demand and/or weather conditions
- Implement/optimize chilled/hot water temperature set point reset based on weather and load conditions
- Optimize and reset condenser water temperature set points based on outside air wet bulb temperature
- Control and optimize condenser water pump speeds based on chiller load and condenser water differential temperature
- Optimize cooling tower fan staging and fan speed control
- Optimize chiller staging control for overall maximum plant efficiency
- Automate and optimize switching between heating and cooling based on weather and/or room conditions(1)
AHUs
- Implement on/off scheduling and optimal start/stop for applicable units
- Implement night setback for applicable units•Implement demand-based ventilation for tower units
- Implement single zone VAV strategy for retail space to improve comfort control and save energy
- Optimize discharge temperature set points for tower AHUs based on weather and/or room conditions(1).
Notes 1. Room controls need to be upgraded for BAS to gather room conditions data.
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