Theoretical and experimental investigation into anti-idling A/C system for trucks

• A mathematical model is developed and verified using a built test-bed.
• Thermal and performance characteristics of an anti-idling truck A/C system are investigated.
• It is shown that variable speed fans have significant effects on the COP in different conditions.
• A point of optimum COP can be found by changing the fans speed for any operating condition.
• Anti-idling A/C systems equipped to variable speed control can significantly save environment.

In this study, a recently developed truck anti-idling air conditioning (A/C) system is investigated. A mathematical model is developed to simulate the thermodynamic and heat transfer characteristics of the A/C system and calculate the coefficient of performance (COP). Utilizing environmental chambers and a number of measuring equipment, an experimental setup is built to verify the accuracy of the mathematical model and to perform a comprehensive study on the performance of the system for a wide range of operating conditions. A good agreement between the simulation and the experimental data, with a maximum discrepancy of 10.6%, is achieved. The results show a range of 0.5–1.7 for the system COP under a variety of operating condition. The parametric study shows that for any cooling demand, ambient and indoor air temperatures, there is a point of optimum COP that can be achieved by adjusting the condenser and evaporator fans speed.