HEAT AND MOISTURE TRANSFER THROUGH CLOTHING

Abstract

The UC Berkeley Comfort Model is a helpful simulation tool for the assessment of thermal comfort in non-uniform environments. A major element of the model is the implementation of a clothing node, which considers both heat and moisture capacitance of clothing. Heat capacity of the clothing has been demonstrated to be important when considering transient effects. Moisture capacitance is important to correctly model evaporative heat loss from the body through clothing. The moisture model uses the regain approach to calculate the amount of moisture that a specific fabric will absorb at a given humidity. NOMENCLATURE A area (m) c specific heat capacity (J/kgK) C heat capacity (J/K) fcl clothing surface area factor F view factor h heat transfer coefficient (W/mK) hfg heat of vaporization of water (kJ/kg) i clothing vapour permeation efficiency I clothing insulation (clo) Lr Lewis ratio (K/kPa) m mass (g) p vapor pressure (kPa) Q heat (W) R regain content (%) t time (s) T temperature (K) v velocity (m/s) w skin wettedness α absorption coefficient ε emission coefficient φ relative humidity σ Stefan-Boltzmann constant (W/m 2 K 4) θ temperature (°C) Suffix a air cl clothing c convective e evaporation m mean n nude r radiative s solar