An algorithm for calculating fresh air age in central ventilation system

【Abstract】 Fresh air age is an important index to evaluate indoor environment. The conventional method for measuring or calculating fresh air age is only suitable for simple ventilation systems and not for central ven-tilation systems. In this paper, an algorithm for calculating fresh air age in central ventilation system is pre-sented, which is based on the analysis of air flow in duct and air mixing. An example is given to illustrate the algorithm. The fresh air age in every ventilated room and duct can be acquired after all rooms and duct are directly calculated in turn without iteration. The algorithm is suitable for different central ventilation sys-tems.更多还原