I am trying to simulate the design cooling load of a simple conditioned building with no ventilation but with cooling and heating set point. However the "design sensible cooling load" I've got is only about 20W/㎡, which is too small compared to the results I calculated with CLTD method and by TRNSYS(about 140W/㎡, a normal value by my experience).
I examined output variables and had found all values under "surface inside/outside face convection heat gain rate" to be negative, meaning that the building loses heat to its surroundings all the time. That is apparently abnormal since it is also shown in output variables spreadsheet that surface inside temperature have always been lower than surface outside temperature for all the hours of design day.
Below are my IDF file (Google Drive shareable link, sorry for the inconvenience since I don't have enough points to be able to upload file directly): https://drive.google.com/file/d/0B_io87UPE7gmV0tZSFl4VHVNSkE/view?usp=sharing
Deeply appreciate it if anybody could come to my aid.