Natural vs. blocked ventilation in naturally ventilated buildings - the effect of finite and decoupled sources

Abstract

Naturally ventilated buildings harness freely-available resources such as internal buoyancy gains and wind forcing in achieving comfortable interior conditions. Although these resources are free, they are time-variable and can be difficult to control. As a result of this the nonlinear interplay between sometimes competing resources may lead to sub-optimal ventilation states. This problem has been explored by a number of previous researches e.g. Flynn & Caufield (Building and Environment, 44, 216-226, 2009) who, in studying these ventilations states, demonstrated complicated transitions characterized by hysteresis even for the simple case of a one-zone building. The objectives of this research are to extend the previous (theoretical) analysis by conducting complementary numerical experiments using sophisticated algorithms capable of describing turbulent, buoyancy driven flow. A further objective of this study is to specifically decouple the source, which was previously assumed to supply both heat and mass to the interior space. Rather, the flow dynamics in a case where heat and mass are supplied independently are examined.