The driven force of fan and pump in the traditional way of the cooling system in cereal combining harvesters comes from crankshaft of the engine by decided transmission ratio.

This experience will be very helpful in the design of test for high by-pass ratio turbofan engine and propeller-fan engine.

The analysis indicates when the flow-ratio of system in high-rise building falls to 50% of the total design flow, the two-way electronic valve on the fan-coil in first floor causes valve failure.