4. Psychrometry – Air-Water Vapor Mixtures

Try these first

1. 1.

   What does DBT stand for?

   Hint

   Think of how we measure normal air temperature.

2. 2.

   What does WBT indicate?

   Hint

   Consider the thermometer with a wet wick.

3. 3.

   What is the definition of relative humidity?

   • A. Actual moisture content
   • B. Moisture content relative to saturation
   • C. Maximum moisture content

   Hint

   Think about saturation levels of moisture.

4. 4.

   True or False: The psychrometric chart helps determine unknown properties of air if two are known.

   • True
   • False

   Hint

   Remember its practical applications.

5. 5.

   You are given a dry bulb temperature of 25°C and a wet bulb temperature of 18°C. Calculate the relative humidity and the dew point.

   Hint

   Use psychrometric relationships for calculations.

6. 6.

   An air conditioning system requires cooling a space from 30°C with 50% RH to 22°C at 40% RH. Describe the processes and how they can be mapped on a psychrometric chart.

   Hint

   Visualize the movement on the chart to understand the changes.