- water-vapor permeance
- паропроводимость
Англо-русский словарь по кондиционированию и вентиляции. 2013.
Англо-русский словарь по кондиционированию и вентиляции. 2013.
Permeance — A unit of measurement for the ability of a material to retard the diffusion of water vapor at 73.4 F (23 C). A perm, short for permeance, is the number of grains of water vapor that pass through a square foot of material per hour at a… … Energy terms
Vapor barrier — A material with a permeance of one perm or less which provides resistance to the transmission of water vapor. [See California Code of Regulations, Title 24, Section 2 5302] … Energy terms
perm inch — a traditional unit of water vapor permeance. The perm value (see above) does not depend on the thickness of the material used as a water barrier. The permeance is the product of the perm value and the thickness, measured in inches. One perm … Dictionary of units of measurement
Perm (unit) — A perm is a unit of permeance or water vapor transmission given a certain differential in partial pressures on either side of a material or membrane.Definitions;US perm:The US perm is defined as 1 grain of water vapor per hour, per square foot,… … Wikipedia