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The thermal comfort inside automotive cabin has been extensively studied for decades. Traditional CFD models provide accurate simulation results of the air temperature distributions inside cabins but at a relatively high computation cost. In order to reduce the computational cost while still providing reasonable accuracy in simulating the air temperature profile inside a mid-sized sedan cabin, this paper introduces a new simulation tool that utilizes a proper orthogonal decomposition (POD) method. The POD method, an interpolation technique, requires only one set of multiple CFD simulations to produce a set of “snapshots”. Later, any simulations that require CFD runs to solve algorithm equation sets can be simplified by using interpolation between the snapshots provided that the geometry of the cabin keeps the same. As a result, the computation time can be reduced to only a few minutes.

Automotive climate control systems are typically equipped with either an orifice tube or a thermostatic expansion valve. The two devices behave differently especially during cycling operation. The variable restriction of the thermostatic expansion valve delays the refrigerant migration when the clutch is disengaged and allows a faster redistribution when the clutch is engaged. The effect of cycling on the performance of two climate control systems, one with a short-tube orifice, and the other with a thermostatic expansion device, was investigated. The cycle period was varied from 10 seconds to 6 minutes. The test results show the change in moisture removal rate, latent capacity, sensible capacity, energy consumption, and coefficient of performance due to cycling. It is shown that the penalty in energy consumption due to cycling depends on the cycle period.