The Role of HVAC Engineers in Achieving Net-Zero Buildings in Thailand’s Hot and Humid Climate

Chakrapan Pawangkarat

Member ASHRAE, Past-President ASHRAE Thailand Chapter

Head of Property and Asset Management, JLL Thailand

22 March 2025

Introduction

Thailand’s tropical climate, with high temperatures and humidity, presents unique challenges for net-zero energy (NZE) buildings—where energy consumption is balanced by renewable energy generation. HVAC engineers are critical in designing systems that minimize energy demand, reduce carbon emissions, and ensure thermal comfort.

Following ASHRAE standards and best practices, HVAC engineers can lead the transition to low-carbon, energy-efficient buildings in Thailand.

Key Roles of HVAC Engineers in Net-Zero Buildings

1. Energy-Efficient HVAC System Design

HVAC systems must be optimized for low energy consumption while maintaining indoor air quality (IAQ). Engineers should:

• Select high-efficiency equipment: Use chillers and VRF systems that meet ASHRAE Standard 90.1 for energy efficiency.

• Right-size systems: Oversized HVAC equipment increases energy use; precise load calculations using ASHRAE Handbook—HVAC Applications are essential.

• Implement radiant cooling: This reduces dependence on high-energy air conditioning, enhancing comfort and efficiency.

2. Humidity Control Strategies

Thailand’s humidity levels often exceed 80%, increasing cooling loads. Effective strategies include:

• Dedicated Outdoor Air Systems (DOAS): Separating ventilation and cooling improves latent heat removal efficiency.

• Optimized dehumidification: Use desiccant dehumidification or enthalpy wheels for better moisture control.

• Demand-controlled ventilation (DCV): CO₂ and humidity sensors ensure ventilation operates only when necessary, reducing energy waste (ASHRAE Standard 62.1).

3. Building Envelope Optimization for Passive Cooling

Reducing cooling demand through passive design is crucial:

• Enhanced insulation and glazing: Use low-U-value materials and high-performance glass to minimize heat gain.

• Shading strategies: External shading devices, green facades, and reflective roofing lower cooling loads.

• Natural ventilation integration: Where possible, mixed-mode ventilation should be used to reduce mechanical cooling dependency.

4. District Cooling for Large Developments

For high-density urban areas and large developments, district cooling is a key strategy for reducing carbon emissions. HVAC engineers must:

• Design and integrate district cooling systems: Centralized cooling plants improve efficiency by operating chillers at optimal load conditions.

• Leverage thermal energy storage: Ice or chilled water storage shifts cooling loads to off-peak hours, improving grid stability.

• Ensure high-efficiency distribution: Well-designed piping networks minimize losses, optimizing system performance.

5. Smart Building Management Systems (BMS) & Controls

Intelligent control systems help maximize HVAC efficiency. Engineers should:

• Implement advanced control strategies: Utilize occupancy-based cooling, predictive algorithms, and adaptive setpoints.

• Integrate real-time monitoring: Sensors for temperature, humidity, and CO₂ levels optimize IAQ while reducing energy use.

• Leverage AI & IoT: Smart analytics detect inefficiencies and optimize system performance automatically.

6. Renewable Energy Integration for HVAC Systems

Net-zero buildings require on-site renewable energy to offset HVAC energy use. Engineers should:

• Optimize solar-powered cooling: PV-powered chillers can help offset grid reliance.

• Integrate district cooling with renewable energy: Using solar and waste heat recovery can further enhance sustainability.

• Follow ASHRAE Standard 189.1: This standard provides guidance for integrating renewable energy into high-performance buildings.

7. Commissioning & Continuous Performance Optimization

Ensuring HVAC systems perform as intended is critical for net-zero success. Engineers play a key role in:

• Commissioning & re-commissioning: Ensuring systems meet design performance (ASHRAE Standard 202).

• Retro-commissioning for existing buildings: Optimizing HVAC performance to support carbon reduction goals.

• Occupant education & training: Facility teams must understand how to operate and maintain efficient systems.

ASHRAE Standards for Carbon Reduction

Several ASHRAE standards and guidelines support carbon reduction efforts in HVAC design:

• ASHRAE Standard 90.1 – Energy efficiency standards for buildings.

• ASHRAE Standard 62.1 – Ventilation for acceptable indoor air quality.

• ASHRAE Standard 189.1 – High-performance green buildings, including renewable integration and carbon reduction.

• ASHRAE Standard 202 – Commissioning processes to ensure optimized HVAC performance.

• ASHRAE Decarbonization Guide – Provides strategies for reducing carbon emissions in buildings.

Conclusion

HVAC engineers are at the forefront of Thailand’s net-zero transition. By integrating energy-efficient design, humidity control, passive cooling, district cooling, smart controls, and renewable energy, they can drive significant carbon reductions while maintaining occupant comfort.

By following ASHRAE guidelines and embracing innovative solutions, HVAC professionals can make Thailand’s buildings more sustainable and climate-resilient.

Would you like to add real-world case studies or local regulatory references?

Acknowledgement:

"This article was generated with the assistance of ChatGPT, an AI language model by OpenAI, and subsequently reviewed and edited by the author."