Dynamic thermal environment and thermal comfort.

Area of Science:

• Building Science
• Environmental Psychology
• Human Thermal Comfort

Background:

• Conventional HVAC systems with tight temperature control often fail to maximize occupant thermal comfort.
• Stable indoor environments lead to increased energy consumption and CO2 emissions.
• Reduced exposure to thermal variations may impair the human body's natural thermal adaptability.

Purpose of the Study:

• To investigate the reasons behind superior thermal comfort in naturally ventilated buildings compared to air-conditioned ones.
• To explore the principles of the adaptive thermal comfort model.
• To address unanswered questions regarding the creation of comfortable and healthy indoor environments.

Main Methods:

• Review of field investigation data comparing free-running and air-conditioned buildings.
• Analysis of climate chamber experiments on airflow preferences.
• Synthesis of research findings on thermal comfort over recent decades.

Main Results:

• Occupants report higher thermal comfort and wider acceptable temperature ranges in naturally ventilated spaces.
• Dynamic airflow, particularly natural wind, is preferred over mechanical ventilation for cooling.
• Human acceptance of thermal conditions is higher in environments that allow for natural variation.

Conclusions:

• The adaptive thermal comfort model provides a framework for understanding occupant responses to dynamic environments.
• Designing buildings that incorporate natural ventilation and airflow can improve thermal comfort and reduce energy use.
• Further research is needed to fully understand the mechanisms of thermal adaptation and optimize indoor environmental design.