This paper deals with the description and determination of the purging flow rate, UP for ventilation systems or equivalent flow systems. The regional purging flow rate and its use are discussed and proposed. By using the mass conservation principle, UP is embodied in various accessible mathematical expressions in terms of the transfer probability. Some UP-related parameters are described. A Markov chain model is proposed for determining the transfer probability and exploring several useful ventilation indices.
The utilization of Hybrid Solar Systems in buildings allowed a rational use of energy required to obtain proper comfort conditions inside the building itself. During some research programmes carried out at !CITE, prototypes of test cells capable of supplying significant information on the energetic behaviour of technologically innovative building envelopes for passive and hybrid solar control, have been designed and built.
The use of local exhaust is considered to be the most effective way to control pollutant dispersion from intense sources, such as in kitchens, in toilets, as well as in copy machine rooms. The optimum air exhaust rate required to prevent pollutants from escaping into the major occupant areas very much depends on the natural air exchange rate(AER) between the hooded room and the major room space. This paper presents a mathematical model and a test procedure of using tracer gas technique to quantify the AER.