Question

For maximum cooling efficiency, an air cooler should be placed:

• A. Facing the window
• B. Away from the window
• C. In the center of the room
• D. Near the ceiling

Hint:

The key to effective evaporative cooling is ventilation. An air cooler needs to draw in dry air and exhaust humid air. The ideal setup is: Cooler at one window (drawing air in) and another window open across the room (pushing air out). Never operate an air cooler in a completely sealed room.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question asks for the optimal placement of an air cooler in a room to achieve maximum cooling efficiency.

Step 2: Detailed Explanation:
The efficiency of an air cooler is based on the rate of evaporation, which is highest when the air being drawn into the cooler is hot and dry.
Placement Analysis:

• Away from the window / In the center of the room: If an air cooler is placed inside a closed room without ventilation, it will draw in the room's air, cool it, and add humidity to it. It will then circulate this same air, which is now cooler but more humid. As the humidity inside the room increases, the rate of evaporation from the cooler's pads decreases significantly. This drastically reduces the cooling efficiency, and the room can become stuffy and humid.

• Near the ceiling: This is not a practical or efficient placement. Cool air is denser than warm air, so it naturally sinks. Placing the cooler high up would work against this natural tendency.

• Facing the window: This is the best placement. "Facing the window" is interpreted as placing the unit at an open window or door. This allows the cooler to continuously draw in fresh, hot, and less humid air from outside. The fan then blows the cooled air into the room. For this setup to be most effective, another window or door on the opposite side of the room should be slightly opened to create cross-ventilation, allowing the humid indoor air to be pushed out. This constant supply of fresh, dry air maximizes the potential for evaporation and, therefore, cooling.

Step 3: Final Answer:
To ensure a continuous supply of fresh, dry air for evaporation, the air cooler must be placed at a source of ventilation, such as an open window. Therefore, placing it facing the window is the most efficient setup.