Psychrometrics
Psychrometrics, the study of moist air, gives us some guidance in designing a comfortable indoor environment. This study (see psychrometric chart) takes into account air temperature, air movement, relative humidity and the latent heat of water vapor (which cools as it evaporates but gives up heat as it condenses when we air condition our space, increasing the cooling load).
Human comfort, however, is dependent on not just air temperature, velocity and humidity, but also metabolic activity level, amount of clothing, mean radiant temperature of room surfaces, radiant asymmetry, air turbulence, air temperature stratification, floor temperature and even colors and mood. In fact, studies have demonstrated that perception of comfort is quite subjective and varies among body types and geographic origin.
In addition, perception of indoor comfort is also dependent upon odors, glare from sunlight, glare from ceiling lights and monitor screens, furniture crowding, aesthetics (such as color and style), noise and vibration levels, ergonomics and personal stress. Each of these elements, then, become important design considerations in a house built for human satisfaction.
