1982-08-04 Regular Meeting La Porte City Council

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. w BID SPECIFICATIONS MODEL 72~2d y • FOR 72,000 BTU INDEPENDENT DIESEL ENGINE POWERED ' AIR CONDITIONING SYS`1'EM ® General Specifications: The air conditioning system shall be powered by an independent auxiliary diesel engine and shall have a, rated output capacity of 72,000 BTU at 95o ambient, independent of the bus engine speed. Engine-Compressor Unit: The compressor shall be twin flat-mounted Tecumseh Model H.G. 1000, or equal, with a cubic capacity (displacement) of 20.6 cu. in. (337 cu. cm.) and shall be driven by a V-belt from the auxiliary engine at 2200 RPM. The compressor shall be equipped with electric clutchs. .One compressor operates continuously. The:..second compressor is controlled by a thermostat. The auxiliary engine shall be a three-cylinder, water cooled Yanmar , industrial diesel engine operating at 3000 RPM. The auxiliary engine `~ shall be connected to the bus electrical system for ~starting.~ The auxiliary engine shall have dual controls: one set of controls located• within easy reach of the driver and another set of controls at the engine-compressor unit for convenience and safety during service and maintenance. The engine-compressor unit shall be mounted in the skirt of the bus in a space 63" long (157.5 cm.); 24" high (60 cm.); 27}" depth (68.75 cm) .~ ' Electrical Power Supply: The air conditioning system components shall be powe~r.ed by a 60 amp, 24 volt alternator driven by the auxiliary engine. The auxiliary engine shall be connected to the battery of the vehicle for starting. Condenser: The condenser shall be aluminum fin-copper tubing rectangular coil with one 18" axial fan powered by the auxiliary engine to provide an air flow of 4200 CFM through the condenser. The condenser assembly shall be incorporated into the engine compressor unit. The condenser fan shall draw fresh air from the outside of the bus rather than dirty air from underneath the vehicle. Evaporator: Two evaporator assemblies shall be provided, with one evaporator assembly incorporated into the air duct on each side of the passenger compartment. The evaporator assembly shall be designed to draw in heated air above the level where cool air is distributed to utilize natural air flow for maximum efficiency and effective cooling. Each evaporator shall have two 8" axial fans (10" on LR duct) powered by 1/4 H.P., 24 volt D.C. motors with an airflow of at least 1100 CFM each. The aluminum fin-copper tubing rectangular coil shall be protected from dirt by a washable foam-type filter. Eacli evaporator shall have an externally equalized thermostatic expansion valve. ' Filter/Dryer: A high capacity filter/dryer shall be incorporated in the air conditioning system to remove moisture from the refrigerant. Receiver: The receiver shall ]lave a capacity equal to the R-12. refrig- erant charge required for the system. G3