Patent ID: 9623722
Date: 2017-04-18
CPC Classifications: B60H,B61D

Claim:
1. A ventilation system for a passenger transit vehicle, the passenger transit vehicle comprising a passenger compartment, the ventilation system comprising: a) a variable speed fan for drawing outside air from an air intake located on an exterior surface of the passenger transit vehicle and providing the outside air to the passenger compartment, the speed of the variable speed fan being controlled based at least in part on an ambient temperature and a passenger load, wherein within a given ambient temperature range, the speed of the variable speed fan is controlled such that the air speed produced by the variable speed fan increases with increasing ambient temperature or passenger load; b) an air diffuser positioned within an upper portion of the passenger compartment, the air diffuser comprising a plurality of air outlets directed into the passenger compartment for directing air from the variable speed fan towards passengers that travel within the transit vehicle; c) a duct system fluidly connecting the variable speed fan and the air diffuser, the duct system having a length and a cross sectional area, wherein the cross sectional area decreases along the length of the duct system for providing substantially constant air pressure along the length of the duct system, the air diffuser running substantially along the length of the duct system of decreasing cross sectional area, the length of the duct system of decreasing cross sectional area being positioned within the upper portion of the passenger compartment.