Michael, The error you are getting is that the zone temperature / zone air flow model is not converging in type56. It is a bit hard to tell the cause of the problem from looking at the *.lst file. If I had to make a wild guess as to the cause of the problem, Type56 allows you to specify a constant convection coefficient or will calculate a convection coefficient for the inside surfaces of walls (and floors, and ceilings). The internally calculated convection coefficient depends on the difference (and on the sign of the difference) between the surface temperature and the air temperature. I would guess that something in the way that you have defined the cooled ceiling is causing the convection coefficient not to converge; perhaps the cooled ceiling has too large a capacity, perhaps the inlet temperature is so low that the surface temperature is not reasonable, perhaps the controls on whether flow is going to the chilled ceiling do not have enough hysteresis. You might start by trying to get the model to run with a constant convection coefficient for the chilled ceiling. Kind regards, David On 5/2/2012 07:43, e0526036@student.tuwien.ac.at wrote: Dear TRNSYS-users, -- *************************** David BRADLEY Principal Thermal Energy Systems Specialists, LLC 22 North Carroll Street - suite 370 Madison, WI 53703 USA P:+1.608.274.2577 F:+1.608.278.1475 d.bradley@tess-inc.com http://www.tess-inc.com http://www.trnsys.com |