Thermal comfort

Thermal comfort has physiological, subjective, cultural aspects. Comfort requirements may have an important impact on energy use.

Related questions

Because the physiological basis of thermal comfort (the human thermoregulatory system) is complex. (In particular, it involves dynamics such that steady-state models are only valid for persons in steady-state conditions). The human body uses a variety of processes in order to compensate for thermally non-neutral environments, of which sweating and shivering are the most visible examples. Because personal, psychological and cultural differences are involved. Because, even when trying to reduce the problem to a heat balance, Conduction, convection, radiation, moisture exchange and metabolism play a role physical variables involved are much more than air temperature: radiant temperature (which can be considered to vary according to the angle), humidity, air velocity, clothing and activity. The geometry of the human body plays a role, and this naturally does not make things easier.

If we follow ASHRAE 55 and define thermal comfort as a "condition of mind that expresses satisfaction with the thermal environment and is assessed by subjective evaluation", thermal comfort appears fundamentally difficult to quantify.

The famous DuBois formula relates body area A to body mass m and height l as \( A = 0.2025 m^{0.425} l^{0.725} \)