Thermal comfort and assessment
This ﬁrst chapter introduces you to temperature, the variations of which provides the motive force in heat transfer, and heat energy, the ﬂow and transport of which in air, water and steam is the essence of much of heating, ventilating and air conditioning design. Its main focus, however, is on the topic of thermal comfort and the assessment of indoor climates, in which people live and work, to establish levels of comfort. The American Society of Heating Refrigeration and Air Conditioning Engineers (ASHRAE) deﬁnes thermal comfort as ‘that condition of mind in which satisfaction is expressed with the thermal environment’. The accurate assessment of building heat losses and gains, the type of comfort systems selected and the regimes of control of the comfort systems are all directed towards achieving this deﬁnition.