In building design and construction, energy efficiency does not necessarily equate to good thermal comfort for occupants.
In fact, human thermal comfort is rather difficult to analyze because it is as much psychological as it is physiological. The notion of “comfort” is a personal feeling – not a quantifiable metric like the kilowatt-hour is for electricity.
Think about it – who has not been in a room where one person claims to be uncomfortably hot while someone close by exclaims to be cold?
So, how can we empirically evaluate occupant comfort? Enter Professor Povl Ole Fanger.
Predicted Mean Vote (PMV)
Professor Fanger was an expert on the health effects of indoor environments. During the 1980′s, he introduced a seven-point scale to asses the thermal comfort of a large number of individuals.
This scale provided the basis for taking surveys of large samples of people regarding how they felt under varying activity levels, clothing levels, and interior environmental conditions.
Fanger also determined that the average value of the numerical survey results could be predicted.