[BLDG-SIM] Cooling load in EPlus not similar to RESFEN3.1

[Rohini Brahme]

I am simulating a typical residence (Brownsville, TX, weather file) using EnergyPlus. The assumptions are similar to the assumptions for RESFEN 3.1. The heating load is similar to that of RESFEN, but the cooling is about 1/3rd. I have been trying to figure what it is that I am missing for past couple of days, but with no luck. The current file has a HVAC system, but even with purchased air, the ratios are same.  One thing that I am not simulating is the natural ventilation (which RESFEN simulates. It uses Enthalpic – Sherman-Grimsrud method). So, if any one can tell me where I can find a description of this method, that will be great. Another issue could be the unconditioned attic and the conditioned living space interaction. Any ideas on what the assumptions are in RESFEN regarding this? Also, does RESFEN3.1 include any dehumidification?

Thanks. Any pointers are appreciated.

Rohini