Chris,

If you are having trouble with the sunspace command in Equest, and you can't find a suitable explanation in the Equest manual. I'd suggest you to to the DOE-2 web site at LBNL and download the DOE-2.1 OCR manuals. The sunspace command was introduced in the DOE2.1d version, which is most likely what Equest is using. Hence, you'll find more of an explanation in the DOE-2.1 manuals. Most likely, you are the cause of the problems since it appears that you've pinched off the flow in the ventilation system that is causing it to crash. For starters, I'd suggest running it again and use as many of the defaults as possible, changing on those that you must change one at a time. I believe that one of the SAMP files that comes with DOE-2 has a sunspace example that you can look at for the defaults.

In addition, if you are trying to evaluate the heating contribution of a sunspace you can use several old packages. For example, the SLR method used to cover sunspaces, and althought the simulation is not widely available for this it is based on the PASOLE program that was written by Bob McFarland, which is a rather sophisticated code that used Russian nozzle coefficients for simulation of the trombe wall and other features. The SLR coefficients are still available in the GKSR book in the appendix. Copies of the old SLR manuals can be had from inter-library loan, or perhaps from NTIS (there were 3 volumes).

In addition, there is the SERIRES program, which is still available from NREL, now called SUNCODE, and there is FCHART. The SERIRES program was also a "strong" simulation program written by Palmiter and Wheeler at Ecotope. It remains one of the basis for the ASHRAE Standard 140 accuracy tests. SERIRES is a finite difference simulation program that is accurate but somewhat limited to specific cases of passive solar architecture.

FCHART will also simulate sunspaces using a direct gain passive solar using the un-utilizability method, which is explained in the Duffie-Beckman Solar Engineering textbook.

You might even consider using an ensemble of simulations to bound your answer to make sure what you are doing is reasonable.

Jeff S. Haberl, Ph.D.,P.E., FASHRAE