| CALOR-IN | and CALOR-OUT | QUANTITIES | | |
| Item No. | Name | Symbol | Definition | Remarks |
| 14-11.1 | heat, amount of heat fr quantité (f) de chaleur, chaleur (f) | Q | difference between the increase of the total energy of a physical system and the work done on the system, provided that the amounts of substances within the system are not changed NOTE A supply of heat may correspond to an increase of thermodynamic temperature or to other effects such as phase change or chemical processes. | See ISO 80000-5, item 5-18. The heat transferred in an isothermal phase transformation should be expressed as the change in the appropriate thermodynamic functions, e.g. T∙∆S, where T is thermodynamic temperature (item 14-5.10) and S is entropy (see ISO 80000-5). |
| 14-11.2 | heat flow rate fr flux (m) thermique | Φ | rate at which heat (item 14-11.1) crosses a given surface. | See ISO 80000-5, item 5-7. For physiological kinds of heat transfers see items 14-11.7 to 14-11.11, which do not apply to hypothermia and hyperthermia. |
| 14-11.3 | heat flow rate, density areic heat flow rate, fr densité (f)de flux thermique, flux thermique surfacique | q, φ | q=Φ/A where Φ is heat flow rate (item 14-11.2) and A is area (item 14-5.3) | See ISO 80000-5, item 5-8. |
| 14-11.4 | thermal conductivity fr conductivité(f) thermique | λ, (κ) | areic heat flow rate (item 14-11.3) divided by temperature (item 14-5.10) gradient | See ISO 80000-5, item 5-9. |
| 14-11.5 | coefficient of heat transfer fr coefficient(m) de transmission thermique | K, (k) | areic heat flow rate (item 14-11.3) divided by thermodynamic temperature (item 14-5.10) difference | See ISO 80000-5, item 5-10.1. |
| 14-11.6 | surface coefficient of heat transfer fr coefficient(m) de transmission thermique de surface | h, (α) | q = h(Ts-Tr) where q is areic heat flow rate (item 14-11.3), Ts is the thermodynamic temperature (item 14-5.10) of the surface and Tr is a reference thermodynamic temperature (item 14-5.10) characteristic of adjacent surroundings | See ISO 80000-5, item 5-10.2. |
| 14-11.7 | combined non-evaporative heat transfer coefficient fr coefficient (m) combine de transmission thermique sans évaporation | h | h = hr + hc + hk where hr is the linear radiative heat transfer coefficient, hc is the convective heat transfer coefficient, and hk is the conductive heat transfer coefficient. | The linear radiative heat transfer coefficient hr can only be used for small temperature differences. |
| 14-11.8 | conductive heat transfer fr transmission(f) thermique par conduction | Φk | proportional to temperature gradient and area of contact | The determining factor depends on the thermal conductivity of the conduction medium. |
| 14-11.9 | convective heat transfer fr transmission (f) thermique par convection | Φc | convective heat transfer coefficient times temperature difference times exchange area | |
| 14-11.10 | radiative heat transfer fr transmission (f) thermique par rayonnement | Φr | radiation proportional to (T1^4-T2^4) and area of the surface, where T1 and T2 are thermodynamic temp-eratures (see ISO 80000-5, item 5-1) of two black surfaces, for non totally black surfaces, an additional factor less than 1 is needed | If (T1-T2)/T is small (where T= (T1 + T2)/2 then approximately (T1^4-T2^4) = 4T^3 (T1-T2). Hence 4σT^3 with σ the Stefan-Boltzmann radiation constant can be treated as a linear radiative heat transfer coefficient. |
| 14-11.11 | evaporative heat transfer fr transmission (f)thermique par evaporation | Φe | evaporative heat transfer coefficient times water vapour pressure difference between skin and environment times exchange area | The water vapour pressure difference is measured in Pa, in physiology in kPa. |
| 14-11.12 | evaporative heat transfer coefficient fr coefficient(m) de transmission thermique par évaporation | he | areic heat flow rate divided by water vapour pressure difference between the surface and the ambient gas | h is measured in W/(m² · Pa), while the three other heat transfer coefficients hr, hc, hkare measured in W/(m² · K). |
| 14-11.13 | cold receptor threshold fr seuil (m) de récepteur au froid | Ŧc | threshold of cold-sensitive free nerve-ending | Cold and warm receptors are specialized neurons, which transfer signals to the temperature-regulation centres. These receptor detection thresholds are the smallest difference in temperature that is "felt", but these are not fixed values, as they depend on the extent of adaptation to an ambient temperature. |
| 14-11.14 | warm receptor threshold fr seuil (m) de récepteur au chaud | Ŧw | threshold of warm-sensitive free nerve-ending | See the Remark in 14-11.13 |
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