Sol-air temperature

Sol-air temperature
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "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

Δ Q i r

= 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

References

See also