heat of evaporation


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heat of e·vap·o·ra·tion

the heat absorbed in the evaporation of water, sweat or other liquid; for water it amounts to 540 cal/g at 100°C.

heat of e·vap·o·ra·tion

(hēt ē-vap'ŏr-ā'shŭn)
Heat absorbed in the evaporation of water, sweat, or other liquid; for water it amounts to 540 cal/g at 100°C.
Synonym(s): heat of vaporization.

heat of evaporation

The heat absorbed per unit of mass when a substance is converted from a liquid to a gas, such as the change of water to steam when it is heated sufficiently. For water, the amount of heat required to transform water into steam is 540 cal/g of water.
See also: heat
References in periodicals archive ?
Skin wettedness was determined in this case as w = sweat rate x hfg/[E.sub.max], where hfg is latent heat of evaporation (0.68 W x h/g [1050 Btu/lb]) and SR is the sweat rate.
The principal of evaporative cooling is well-known; a constant energy, totally natural phenomena in which heat is extracted from air as a result of the latent heat of evaporation. The Econoclim has a water circulation system and a series of humidification mats which are kept wet by the recirculation system.
The latent heat of evaporation is 975 Btu/lb of water evaporated per minute.
a--thermal diffusivity, [m.sup.2]/s; B--Spalding transfer number; [C.sub.l]-droplet drag coefficient; [c.sub.p]--mass specific heat, J/(kg K); Fo--Fourier number; g--evaporation velocity, kg/s; k+r--conduction and radiation; L--latent heat of evaporation, J/kg; m--vapour mass flux, kg/([m.sup.2]s); Nu--Nusselt number; p--pressure, Pa; P--symbol of free parameter in heat-mass transfer; q--heat flux, W/[m.sup.2]; r--radial coordinate, m; T--temperature, K; [eta]--non-dimensional radial coordinate; [lambda]--thermal conductivity, W/(m K); [mu]--molecular mass, kg/kmol; [rho]--density, kg/[m.sup.3]; [tau]--time, w--velocity.