heat of vaporization

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heat of vaporization

n.
The amount of heat required to convert a unit mass of a liquid at its boiling point into vapor without an increase in temperature.
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Noun1.heat of vaporization - heat absorbed by a unit mass of a material at its boiling point in order to convert the material into a gas at the same temperature
heat of transformation, latent heat - heat absorbed or radiated during a change of phase at a constant temperature and pressure
References in periodicals archive ?
Indeed, the latent heat of evaporation of water ([L.sub.v] [approximately equal to] 45 kJ [mol.sup.-1]) when converted to molecular units is [l.sub.v] = 0.47 eV.
The evaporative heat transfer via skin diffusion (Ed, W x [m.sup.-2]) was calculated as [E.sub.d]=[lambda] x m x ([P.sub.s]- [P.sub.a]), where [lambda] is the latent heat of evaporation of sweat (2430 J x [g.sup.-1]), m is the permeance coefficient of the skin (1694 x [10.sup.-4] g x [s.sup.-1] x [m.sup.-2] x mm[Hg.sup.-1]), [P.sub.s] is the partial water vapor pressure at the skin surface (mmHg), [P.sub.a] is the partial water vapor pressure in ambient air (mmHg), and [A.sub.D] is the body surface area ([m.sup.2]) modified from Fanger (26).
This heat, called the heat of evaporation, equals a whopping 970 BTU/lb.
Where PET is the potential evapotranspiration (mm/day), A is the slop of the saturation vapour pressure temperature curve (kpa/[degrees]c), [R.sub.n] is the net radiation (Mj/[m.sup.2].day), G is the soil heat flux density (Mj/[m.sup.2].day) and assumed zero in this study because of the daily time step used for PET computation, 1 is the latent heat of evaporation (Mj/kg), [gamma] is the psychrometric constant (kpa/[degrees]c).