©2026 This excerpt taken from the article of the same name which appeared in ASHRAE Journal, vol. 68, No. 5, May 2026.
Dispelling Thermal Comfort Myths, Part 1: Foundations for Applying ASHRAE Standard 55-2023
By Asit Kumar Mishra and Robert Bean
Asit Kumar Mishra, Ph.D., is research fellow, University College Cork, Cork, Ireland. Robert Bean, RET, P.L..(Eng.) is a retired practitioner from Alberta, Canada.
Thermal comfort design is often plagued by certain myths and misconceptions that limit effective practice and implementation of existing standards. This leads to both energy waste and occupant dissatisfaction and the epicenter of thermostat wars. Thermal discomfort is a known deterrent to productivity and academic learning. This first part of a two-part column examines four common thermal comfort myths, provides evidence-based guidance for proper application of ASHRAE Standard 55-2023 and demonstrates how a holistic understanding of all thermal comfort parameters can improve design outcomes in architectural, enclosure, interior and HVAC systems. By dispelling these foundational myths, practitioners can create conditions for people to perceive thermal comfort and enable energy efficient environments and systems that are truly occupant centric, healthy and sustainable.
ASHRAE Standard 55-2023, Thermal Environmental Conditions for Human Occupancy,1 provides the foundation for thermal comfort conditions in buildings across multiple regions worldwide. However, widespread misconceptions about the standard and thermal comfort principles continue to limit its effective application. These myths range from oversimplified assumptions about temperature control to fundamental misunderstandings about the factors that influence human thermal perception.
The standard defines thermal comfort as “that condition of mind that expresses satisfaction with the thermal environment and is assessed by subjective evaluation.” This seemingly simple definition encompasses a complex interplay of six key factors: four environmental parameters (air temperature [ta], mean radiant temperature [MRT], humidity [H] and air velocity [V ]) and two personal factors (clothing insulation [clo] and metabolic rate [met]).2 Additionally, under low met rates (<1.3) and clothing (<0.7), five local factors must also be assessed.1 Understanding the relationships of the 11 factors is crucial for effective design practice.
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