Watt value of sunlight on a window

[Sinexus]

If the sun shines on a window at some angle, are there any equations one could use to calculate the Watt-value at a given time?

 

[willard3]

What are you trying to do, calculate the solar loading on glass?

ASHRAE tables give irradiation at solar maximum and you could, through simple geometry, find the solar component at other angles.

You would first have to find out the incident angle on that date at your latitude and longitude, but these are readily available.

I hope this isn't a homework problem.......

 

[Sinexus]

I'm trying to find out to what extent the sun contributes to the heating of a room when it hits the window at certain angles.

 

[MintJulep]

The method and information is all in ASHRAE Fundamentals.