In addition to my first email, I used the Madison TMY3 file provided in one of the TRNSYS weather folders and it matched exactly with the one I downloaded from NSRDB. Again when I ran a simulation and wrote an output file using Type 25 (printer), the ambient temperature was altered. In the TMY3 file, the first few dry-bulb temperature were -18.3, -18.3, -18.9... and in the output file I wrote after the simulation, the first dry-bulb temperatures were -4.4, -11.35, -18.3...
Is it doing some sort of interpolation?
-- Devin M. Rohan, LEED Green Associate Purdue University Civil/Architectural Engineering drohan@purdue.edu