Sol-air temperature

Sol-air temperature ("T"_sol-air) is a variable used to calculate cooling load of a building and determine the total heat gain through exterior surfaces. It is an improvement over

:$frac\{q\}\{A\}\; =\; h\_o(T\_o\; -\; T\_s)$ where:$h\_o$ = heat transfer coefficient for radiation (long wave) and convection:$T\_o$ = outdoor surroundings' temperature:$T\_s$ = outside surface temperature

This equation only takes into account the temperature differences thus, ignoring solar radiative flux and infrared exchanges from the sky. The "T"_sol-air was then introduced to accommodate these two parameters.

:$T\_mathrm\{sol-air\}\; =\; frac\{T\_o\; +\; (a\; cdot\; I\; -\; Delta\; Q\_\{ir\})\}\{h\_o\}$where:$a$ = solar radiation absortivity of a surface:$I$ = global solar irradiance:$Delta\; Q\_\{ir\}$ = infrared radiation transfer of sky temperature to surface

and is to be used in:$frac\{q\}\{A\}\; =\; h\_o(T\_mathrm\{sol-air\}\; -\; T\_s)$

References

#Fundamentals volume of the "ASHRAE Handbook", ASHRAE, Inc., Atlanta, GA, USA, 2005

#"Heating and Cooling of Buildings", 2nd ed., Kreider, Curtiss, Rabl, McGraw-Hill, New York, USA, 2002

ee also

*HVAC
*ASHRAE
*Active solar
*Passive solar