Building Energy Efficiency Handbook: From Data Collection to Continuous Optimization
Building energy consumption accounts for 40% of global energy use and over 45% of total social energy consumption in China. This handbook systematically covers the technical pathways and practical experience of building energy efficiency from three dimensions: energy monitoring data collection, HVAC system optimization, and intelligent air conditioning control.
Energy Efficiency Technology Roadmap
| Phase |
Objective |
Key Technologies |
Savings Potential |
| Monitoring | Establish energy baseline, detect anomalies | Sub-metering, data acquisition gateways, energy platforms | 5%-10% (eliminate waste) |
| HVAC Optimization | Improve major system efficiency | Sensor feedback control, VFD, hydraulic balancing | 15%-25% |
| System Integration | Eliminate inter-system energy waste | BAS, CO₂ demand control ventilation, scheduling | 10%-15% |
| Predictive Optimization | AI-driven continuous optimization | Machine learning, digital twin, predictive maintenance | 5%-15% |
Step 1: Energy Monitoring & Data Collection
No data, no management. Energy monitoring is the foundation of building energy efficiency.
Collection Point Design Principles
- Sub-metering: Separate metering for HVAC, lighting, power, and special loads
- Key equipment: Individual metering for chillers, pumps, cooling towers
- End circuits: Floor/zone-level metering to locate anomalies
- Data quality: 15min-1hr sampling, >95% data completeness
Collection Solutions
- New construction: RS485/Modbus meters with energy gateway centralized collection
- Retrofit: Split-core current transformers for non-disruptive installation
- Cloud integration: MQTT or HTTP API direct upload, or edge gateway with store-and-forward
Step 2: HVAC System Energy Optimization
HVAC accounts for 40%-60% of building energy consumption — the primary optimization target.
Chilled Water System Optimization
- Chiller plant optimization: Auto-adjust running units based on load, avoid low-load operation
- Supply temperature reset: Dynamic adjustment based on outdoor conditions and end demand
- Condenser water optimization: Fan VFD + tower staging, approach wet-bulb limit
- Hydronic balancing: Differential pressure sensors and valves eliminate overflow/underflow
Terminal System Optimization
- CO₂ Demand Control Ventilation (DCV): Adjust fresh air based on occupancy, avoid over-ventilation
- Temperature setpoint optimization: 26°C summer / 20°C winter, each 1°C saves 6%-8%
- Free cooling in transition seasons: Use outdoor air when enthalpy is lower than indoor
- Fan VFD: Static pressure feedback control, fan power drops with cube of speed
Heating System Optimization
- Boiler staging optimization: Load distribution across multiple boilers
- Supply/return temperature differential: Small delta-T indicates excessive pumping
- Weather compensation: Dynamic supply temperature based on outdoor conditions
Step 3: Intelligent Control & Continuous Optimization
Sensor-Driven Closed-Loop Control
- Temperature sensors → chilled/hot water valve PID control
- CO₂ sensors → fresh air damper/fan speed adjustment
- Differential pressure sensors → pump/fan VFD control
- Flow sensors → cooling/heating energy measurement and efficiency analysis
AI & Predictive Optimization
- Load forecasting: Historical data + weather forecast for proactive strategy adjustment
- Anomaly detection: AI identifies abnormal consumption patterns, auto-alerts
- Digital twin: Virtual model mirrors physical system, simulates and validates strategies
In-Depth Technical Articles
Energy Monitoring & Data Collection
HVAC Energy Optimization
Smart Building & AI
Energy Efficiency Products & Solutions
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Zhiyinghui provides one-stop energy efficiency services from energy audit, solution design, product selection to system integration. Contact our technical team for a customized energy efficiency solution.
