Heating, ventilation, and air conditioning (HVAC) systems are the backbone of building comfort, but they’re also some of the largest energy consumers in commercial buildings. Inefficient operation can drive up energy bills and carbon emissions, making optimization a priority for building managers and sustainability teams alike.

While both chiller-side and air-side systems play important roles, the largest opportunities for energy savings often come from the chiller-side. In fact, up to 70% of HVAC energy consumption comes from chillers, pumps, and cooling towers. Focusing optimization efforts here delivers the most significant impact.

 

Understanding HVAC Energy Consumption: Chiller-Side vs Air-Side

To see why chiller-side optimization matters, it helps to understand how energy is distributed across an HVAC system. Broadly, HVAC systems can be divided into two main parts:

  • Chiller-side: This includes chillers, pumps, and cooling towers. These components generate and circulate chilled water to cool the building.
  • Air-side: This includes air handling units (AHUs), variable air volume (VAV) systems, and ductwork. These components distribute cooled air throughout the building and regulate ventilation.

A typical commercial building dedicates roughly 70% of HVAC energy to chiller-side operations, with the remaining 30% consumed by air-side components. This energy distribution makes chiller-side optimization the most effective lever for reducing overall HVAC energy consumption.

 

Why Chiller-Side Optimization Matters

  1. High Energy Consumption and Savings Potential: Chiller-side systems account for the majority of HVAC energy use, making even small efficiency improvements impactful. Inefficiencies in chillers can quickly translate into massive energy waste. By implementing AI-driven optimization, buildings can reduce chiller energy consumption by 20–40%, unlocking substantial cost and carbon savings.
  2. Complexity Makes Chiller-Side Ideal for AI Optimization: Unlike air-side components which operate relatively simply, chiller-side efficiency is highly dynamic and influenced by many interacting factors:
    • Cooling load fluctuations throughout the day
    • Outside weather conditions
    • Supply and return water temperatures
    • Interaction between multiple chillers within a system

Because of this complexity, traditional rule-based management by BMS often fall short. AI however, can continuously analyze these variables, predict inefficiencies, and recommend or implement real-time adjustments, achieving optimal performance without manual intervention.

  1. Operational Implications: Poor chiller-side performance doesn’t just waste energy, it can also create downstream inefficiencies in air-side systems. Optimizing chiller operation first ensures that air-side components receive consistent cooling, which further improves overall system efficiency.

 

Air-Side Optimization: Important, but Secondary

Air-side systems remain critical for indoor comfort and air quality. AHUs, VAVs, and fans ensure proper ventilation and temperature distribution throughout a building. However, these components consume significantly less energy than chillers, typically only 10-30% of total HVAC energy.

Optimizations such as demand-controlled ventilation or airflow adjustments can reduce air-side energy consumption, but the potential savings are modest – usually 5–15% at most. While these measures are valuable, the largest efficiency gains are still found on the chiller-side.

 

How Akila Approaches Chiller-Side Optimization

At Akila, our approach to chiller-side optimization combines real-time data monitoring with AI-driven insights:

  • Real-time energy monitoring: Continuously tracks chiller performance and identifies inefficiencies.
  • Demand forecasting: Predict upcoming HVAC demand to better plan and schedule chiller output.
  • AI-driven load balancing: Optimizes operations across multiple chillers to reduce energy peaks.
  • Predictive maintenance: Anticipates potential equipment failures to prevent energy waste.
  • Holistic system coordination: Aligns chiller-side operations with building-wide HVAC demands for maximum efficiency.

Buildings using Akila’s platform have seen chiller energy reductions of up to 40%, proving that the most complex part of the HVAC system can also be the most rewarding to optimize.

 

Key Takeaways

  • Chiller-side optimization has the largest impact on energy and cost savings in HVAC systems.
  • Air-side optimization is still valuable for comfort and indoor air quality, but its energy-saving potential is limited.
  • The complexity of chiller operations makes AI a perfect tool for delivering continuous, high-impact efficiency improvements.
  • Building managers seeking the highest return on investment in HVAC optimization should focus first on chiller-side systems.

By prioritizing chiller-side efficiency, facilities can reduce energy consumption, cut costs, and advance sustainability goals, all while maintaining comfort and operational reliability.