Introduction

The recent variability in Singapore’s weather, characterised by hot mornings and sudden afternoon showers, underscores a critical disconnect in how we manage indoor climates. While external conditions fluctuate, office cooling systems often operate on static settings, leading to a common scenario: occupants feeling consistently uncomfortable, often resorting to extra layers indoors.

What is Thermal Comfort?

True comfort in an indoor environment extends beyond simply maintaining a specific temperature. It’s about creating an environment where employees feel at ease—not too hot, not too cold. Thermal comfort is a more nuanced science, influenced by a combination of environmental factors like temperature, humidity, and air movement, as well as personal factors.

Understanding PMV and ASHRAE 55 Standards

The widely recognised Predicted Mean Vote (PMV) index provides a robust framework for evaluating thermal comfort as per ASHRAE 55 Standards (American Society of Heating, Refrigerating, and Air-Conditioning Engineers). Unlike simple temperature readings, PMV considers six key variables:

• Metabolic Rate: The rate of heat generated by the human body’s activity level.
• Clothing Insulation: The thermal resistance provided by clothing, influencing heat exchange with the environment.
• Air Temperature: The ambient temperature of the surrounding air.
• Radiant Temperature: The weighted average of the temperatures of all surfaces surrounding an occupant.
• Air Velocity: The speed at which air moves around the occupant, affecting convective heat transfer.
• Humidity: The amount of moisture in the air, impacting evaporative cooling from the skin.

The PMV scale ranges from -3 (cold) to +3 (hot), with an optimal comfort zone typically falling between -0.5 and +0.5. When HVAC systems are not dynamically adjusted to account for these interacting variables and the fluctuating external conditions, occupants are likely to experience thermal discomfort.

 

This persistent discomfort not only impacts occupant well-being and productivity but also has tangible consequences for building owners and facility managers through increased tenant complaints and potentially higher energy consumption due to inefficient, static operation.

Enhancing Thermal Comfort with Resync’s AI-Driven Solution

That’s why when we were building Resync’s AI-driven ACMV optimisation, thermal comfort was one of the key parameters for us. Our solution addresses this challenge by dynamically managing HVAC systems based on a comprehensive understanding of these thermal comfort parameters, alongside ventilation requirements (CO2 levels for optimal productivity) and chiller performance. By moving beyond simplistic temperature control, we enable buildings to adapt intelligently to both external weather variations and internal occupancy patterns, creating truly comfortable and energy-efficient spaces.

Let’s embrace a more scientific approach to indoor cooling management and prioritise the holistic concept of thermal comfort.

PS: Authored with the help of Gemini

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Interested in improving the thermal comfort balance of your facility?
Contact us at info@resynctech.com or visit www.resynctech.com to learn more.