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thermal comfort

Human thermal comfort describes the state of mind that expresses satisfaction with the surrounding environment. It is affected by six factors:
  • Air temperature is the most common measure of thermal comfort and can easily be influenced with passive and mechanical heating and cooling.
  • Mean radiant temperature is the weighted average temperature of all exposed surfaces in a room. The greater the difference between air temperature and exposed surfaces, the greater the wind chill factor.
  • Wind chill factor (relative air velocity) is the apparent temperature felt on exposed skin due to wind. For example, if cold air is leaking in from a window, the air temperature feels lower than the actual air temperature, hence the increased likelihood of feeling cold, even when the heater is on.
  • Humidity or relative humidity is the moisture content of the air. If the humidity is above 70% or below 30% it may cause discomfort.
  • Activity levels can reduce the heating needs, as lower air temperature is acceptable when occupants have higher activity levels.
  • Thermal resistance of clothing or warm blankets in a bedroom can reduce the need of heating.

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