Natural ventilation is one of the most fundamental techniques to reduce cooling energy usage in buildings. Energy-conscious designers harness the cooling capacity of ambient air to increase indoor thermal comfort and ultimately lessen the necessity for active space conditioning. Hybrid ventilation is the use of natural forces (wind and temperature) to condition a building, with the supplemental use of mechanical forces whenever natural forces are inadequate. The implementation of natural and hybrid ventilation represents an opportunity to make better use of energy consumption for HVAC, by utilizing free natural cooling as much as possible. The goal of this project is to advance the use of natural and hybrid ventilation concepts in building design by assessing the accuracy and usability of current thermal-ventilation models.