1. (a) An optional air conditioning (A/C) unit shall be installed at the center rear or sides of the roof. The configuration of any A/C unit mounted on the bus shall be securely installed so as to minimize the potential for injuries during a rollover accident and shall be equipped with a high impact plastic cover with rounded corners. No portion of any A/C unit may project into the effective space surrounding any emergency exit. No A/C unit may extend outward or downward to such an extent that it would detract from the safe and efficient evacuation of persons by means of the use of an emergency exit.
2. (b) Evaporator cases, lines and ducting (as equipped) shall be designed in such a manner that all condensation is effectively drained to the exterior of the bus below the floor level under all conditions of vehicle movement and without leakage onto any interior portion of the bus.
3. (c) On specially equipped school buses, the evaporator and ducting (if used) shall be placed at sufficient height so as not to obstruct occupant securement shoulder strap upper attachment points. Such clearance shall be provided along the entire length of the passenger area on both sides of the interior, in order to allow for potential retrofitting of new wheelchair positions and occupant securement devices.
4. (d) The body may be equipped with insulation, including sidewalls, roof, firewall, rear, inside body bows and plywood or composite floor insulation to aid in heat dissipation and reflection.
5. (e) All glass (windshield, service and emergency doors, side and rear windows) may be equipped with maximum integral tinting allowed by federal, state or ANSI standards for the respective locations, except that windows rear of the driver's compartment, if tinted, shall have twenty-eight (28) per cent light transmission, plus or minus three (3) per cent.

(Adopted effective May 2, 2007)