[TRNSYS-users] Type506 evap cooler manual

[Constanze.Bongs at csiro.au]

Hi,

Just a short question regarding description of the equations underlying
type 506 in the manual/documentation.
Equation 506.3 describes the calculation of outlet states as following:

Tout=Tin-effsat*Twetbulb

Now I was wondering about the following. Saturation efficiency as
defined by ASHRAE Epuipment Handbook is the following:

Effsat=(Tin-Tout)/(Tin-Twetbulb)

I was assuming this was the same efficiency as the one used by the type.
However, the two equations don't seem to align. Solving saturation
efficiency as defined by ASHRAE for Tout, I get the following
relationship:

Tout=Tin-effsat*(Tin-Twetbulb)
 
With Twetbulb=f(Tin)

Is there an error in the documentation, in my assumptions or does the
type apply a different kind of efficiency?  I would be very grateful for
explanation as I want to cite the calculation formula in my thesis!
Thanks a lot.

Cheers,

Constanze