Design of heat recovery exchanger for indoor air quality and energy efficiency on buses

In nowadays, many people use the buses, to travel to the places in medium or long distance. During the travel time of the bus, the doors are kept close for a long time, thus air-conditioning system tries to maintain optimum condition comfort conditions for the passengers. Even though this system provides thermal comfort, it also disrupts indoor air quality. Hence, indoor air quality become important for intercity buses In this study, a heat recovery device is designed to provide indoor air quality and energy efficiency for intercity buses. The aim of this study is to design the heat recovery device which supplies fresh air to bus cabin for clean indoor environment while maintaining energy efficiency. For intercity buses, three different simulations are carried out to determine the amount of required fresh air and optimum heat recovery device. In the first study, fresh air flow rate is identified considering the carbon dioxide concentration on bus. In the second and third studies, two different heat recovery devices (i.e. flat plate and offset strip fin heat exchanger) are investigated. The effect of various parameters on the effectiveness and sizes of both devices are investigated and compared. These simulations are done with MATLAB software. In conclusion, dimensions and effectiveness of devices are calculated and an optimum heat recovery device is designed.