รายละเอียดเอกสาร

This chapter describes air-conditioning and heating systems for buses, rail passenger vehicles, and fixed-guideway vehicles (all vehicles commonly referred to as ground mass transit vehicles) that transport large numbers of people, often in crowded conditions. Airconditioning systems for these vehicles generally use commercial components, but are packaged specifically for each application, often integral with the styling. Mass, envelope, power consumption, maintainability, and reliability are principal factors. Power sources may be electrical (ac or dc), engine crankshaft, compressed air, or hydraulic. These sources are often limited, variable, and interruptible. Characteristics specific to each application are discussed in the following sections. Design aspects common to all mass-transit HVAC systems include passenger comfort (ventilation, thermal comfort, air quality, expectation) and thermal load analysis (passenger metabolic rate, solar loading, infiltration, multiple climates, vehicle velocity, and, in urban applications, rapid interior load change). Ground mass transit rail applications should follow the recommendations provided by ASHRAE Guideline 23 and ground mass urban bus applications should follow the American Public Transportation Association (APTA) Bus Procurement Guidelines BTS-BPG-GL-001-13.