Enter the outdoor temperature (C), the solar radiation absorptivity, the extra infrared radiation (W/m^2), and the heat transfer coefficient (W/m^2-k) and the global solar irradiance (W/m^2) into the Sol-Air Temperature Calculator. The calculator will evaluate the Sol-Air Temperature. 

Sol-Air Temperature Formula

The following formula is used to calculate the Sol-Air Temperature. 

Tsa = To + (a*I - Q) / h


  • Tsa is the Sol-Air Temperature (C)
  • To is the outdoor temperature (C) 
  • a is the solar radiation absorptivity 
  • I is the global solar irradiance (W/m^2) 
  • Q is the extra infrared radiation (W/m^2)
  • h is the heat transfer coefficient for radiation (W/m^2-K)

How to Calculate Sol-Air Temperature?

The following steps outline how to calculate the Sol-Air Temperature.

  1. First, determine the outdoor temperature (C).
  2. Next, determine the solar radiation absorptivity. 
  3. Next, determine the global solar irradiance (W/m^2). 
  4. Next, gather the formula from above = Tsa = To + (a*I – Q) / h.
  5. Finally, calculate the Sol-Air Temperature.
  6. After inserting the variables and calculating the result, check your answer with the calculator above. 

Example Problem:

Use the following variables as an example problem to test your knowledge.

outdoor temperature (C) = 4

solar radiation absorptivity = 59

global solar irradiance (W/m^2) = 122

extra infrared radiation (W/m^2) = 20

heat transfer coefficient for radiation (W/m^2-K) =100

Tsa = To + (a*I – Q) / h =  ?