heat transmittance

thermal transmittance, U-value

The time rate of heat flow per unit area under steady conditions from the fluid on the warm side of a barrier to the fluid on the cold side, per unit temperature difference between the two fluids.
References in periodicals archive ?
To measure thermal transmission coefficients of windows according to KSF 2278, from the hot box heating (Qt), which is measured using a cold/hot chamber as shown in Figure 1, calibrated hot box heat (Q1) and calibrated specimen fixing panel heat (Qs) are subtracted in order to obtain heat transmittance of specimen (Qn).
PPG Industries aerospace transparencies business is developing coating technology for aircraft cockpit and passenger-cabin windows that reduces solar heat transmittance for more crew and passenger comfort and reduced load on the air-conditioning system for lower operating costs.
The temperature of the inner window surface depends on the outside air temperature and window heat transmittance coefficient.
PPG IndustriesO aerospace transparencies business is developing coating technology for aircraft cockpit and passenger-cabin windows that reduces solar heat transmittance for more crew and passenger comfort and reduced load on the air-conditioning system for lower operating costs.