Consider the automotive climate control system with heater and air conditioner (Figs. 1.20 and 1.21).

a) Design an open-loop heater control system concept using a block diagram. Identify the components are role of each component in the bock diagram.

b) Design a closed-loop heater control system concept using a block diagram. Identify the components are role of each component in the bock diagram.

c) Design an open-loop air conditioner control system concept using a block diagram. Identify the components are role of each component in the bock diagram.

d) Design an closed-loop air conditioner control system concept using a block diagram. Identify the components are role of each component in the bock diagram.

Discuss the difference between open-loop and closed-loop controls in terms of required compo- nents, controller logic as well as advantages and disadvantage.

8 www. C B Cabin 000 1. Recirculation Control 2. Heating Control 3. Heating Unit 4. Cab fan 5. Evaporator 6. 7. 8. Prefilter Valve for draining condensation water Recirculation damper 9. Cab filter A. Air from outside the cab B. Air into the cab C. Recirculation air Figure 1.20: Automotive heating and air-conditioning control system (Source: Volvo CE Wheel Loader Operators' Manual).