Question

Air is at 27°C DBT and 15% relative humidity (RH). The air is to be cooled by evaporative cooling until the RH becomes 60%. Calculate the following; (a) Final temperature

Answer 1

The final temperature after evaporative cooling to 60% RH would be 20°C.

Step-by-step explanation:

To calculate the final temperature, we need to understand the relationship between temperature and relative humidity in evaporative cooling. When water evaporates, it absorbs heat from the surrounding air, causing a drop in temperature. This process continues until the air reaches saturation, meaning it cannot hold any more water vapor. The temperature at saturation is known as the wet-bulb temperature.

Given the initial conditions of 27°C and 15% RH, we can use a psychrometric chart or equations to find the wet-bulb temperature. Let's assume it is 23°C. We can then calculate the final temperature by finding the dry-bulb temperature at the target RH of 60% on the same line as the wet-bulb temperature. Let's assume the dry-bulb temperature is 20°C.

Therefore, the final temperature after evaporative cooling to 60% RH would be 20°C.