Specifications include, but are not limited to: a. Standard Performance: The installed air conditioning system will cool the interior of the bus from 100 degrees to 80 degrees Fahrenheit, measured at three points (minimum) located four feet above the floor on the longitudinal centerline of the bus. The three required points will be: (1) three feet above the center point of the horizontal driver seat surface, (2) at the longitudinal midpoint of the body, and (3) three feet forward of the rear emergency door. The independent temperature reading of each temperature probe inside the bus will be within a range of ± 3 degrees Fahrenheit of the average temperature at the conclusion of the test.; b. High Performance: The installed air conditioning system will cool the interior of the bus from 100 degrees to 70 degrees Fahrenheit, measured at three points (minimum) located four feet above the floor on the longitudinal centerline of the bus. The three required points will be: 47 (1) three feet above the center point of the horizontal driver seat surface, (2) at the longitudinal midpoint of the body, and (3) three feet forward of the rear emergency door; c. Test Conditions: 1. The test conditions under which the above performance standards must be achieved will consist of (1) placing the bus in a room (such as a paint booth) where ambient temperature can be maintained at 100 degrees Fahrenheit; (2) heat-soaking the bus at 100 degrees Fahrenheit at a point measured two feet horizontally from the top of the windows on both sides of the bus, with windows open for two hours; and (3) closing windows, turning on the air conditioner with the engine running at 1250 ± 50 RPM, and cooling the interior of the bus to 80 degrees Fahrenheit, (standard performance) or 70 degrees Fahrenheit (high performance), within 30 minutes while maintaining 100 degrees Fahrenheit outside temperature. The manufacturer will provide test results that show compliance. The contract(s) shall provide facilities for GCPS Fleet to confirm that a pilot model of each bus manufacture meets the above performance requirements; 2. With GCPS Fleet’s approval, the contractor(s) may perform an alternate test under actual summer conditions, which consist of temperatures above 85 degrees Fahrenheit, humidity above 50% with normal sun loading of the bus and the engine running at 1250 ± 50 RPM. After a minimum of one hour of heat soaking, turn on the system and it must provide a minimum of a 20-degree temperature drop in the 30-minute time limit. The A/C System Performance Testing will follow the criteria outline in the first above in paragraphs 3a and 3b.
