For the last 50 years, the design of buildings has generally been based on the assumption that controlling the indoor temperature within narrow limits provides maximum thermal comfort and, in most cases, requires conditioning of the indoor air. This is based on research in climate chambers. However, over the past 25 years, based on field studies in a large number of buildings in use, a new view has been developed, called adaptive thermal comfort, which emphasises the ability of people to adapt in different ways to the temperatures found in unconditioned or hybrid buildings. If it is warmer outside, occupants in these buildings expect it to be warmer inside and adjust accordingly, for example by opening windows or adjusting their clothing.
In such buildings, people are more satisfied with the indoor climate than in buildings with a tightly controlled temperature, because controlling the temperature within narrow boundaries reduces the body’s ability to adapt to changing temperatures. Moreover, tight temperature limits do not lead to higher productivity.
This places demands on the building, which must be designed in such a way that thermal comfort can be achieved as much as possible without conditioning, for example through adequate shading, thermally effective building mass and usable open windows.
Adaptive thermal comfort enables a win-win situation where the indoor climate is more comfortable and less energy is needed.