Simplified model and sensitivity analysis for natural ventilation load in multifamily buildings.

A simplified natural ventilation model for dwellings is developed and used to determine the impact of different ventilation strategies on the building loads and zones temperatures. It deals with the sensitivity of loads and temperatures to classical default parameters as : wind velocity, wind coefficient value, building environment and shielding conditions, and the actual cross section of the openings. All the simulations are performed using the TRNSYS 14.2 simulation software, TYPE56. The results based upon the studied case show that the average cooling load over a reference hot "wave" can reach values up to 15-20 W /m2 if using an adequate ventilation strategy (night free-cooling), and maximal room temperatures can be damped to about 30° C ( 4.5 K lower than maximal outdoor temperature).