Lindeburg Practice Test (Problem HVAC 76)

[mke_sjel]

I’m hoping someone can help be find an equation used in the Lindeburg practice exam. (HVAC 76) The equation is To=A*Tair+(1-A)*Tr. I looked through my Ashrae books and MERM, but couldn't find it. I'm wondering if this is a standard equation? Also where I can determine what A is.

Thanks for the help in advance.

 

[Cwildfrank]

I’m hoping someone can help be find an equation used in the Lindeburg practice exam. (HVAC 76) The equation is To=A*Tair+(1-A)*Tr. I looked through my Ashrae books and MERM, but couldn't find it. I'm wondering if this is a standard equation? Also where I can determine what A is.
Thanks for the help in advance.

If you look in ASHRAE Standard 55-2004 it is on page 20 towards the bottom of the page. They must be using an older version though because they get a slightly different number for A.

Hope this helps!