A building has several rooms with centralized air-conditioner and no temperature regulation. Due to difference in preferences for room temperature the employees are facing problems. Please suggest how can we design a system using this centralized Air conditioner to regulate the temperature of our room/ surroundings.

Help me in Designing a solution for my problem, How it is done to:

1. Develop an On/Off Mechanism

2. Ability of creating 3 or more levels of Cooling

3. Switching On/Off depending upon the presence of the person

The cost Economics should also be justified for the design.