Applying First Law to Psychometric Processes — Lesson 3

This lesson covers the application of the first law to psychometric processes, focusing on both flow and non-flow processes. It explains how moist air is treated as a mixture of two ideal gases - dry air and water vapor. The lesson also discusses the change in internal energy of dry air and water vapor, and how to calculate it. It provides examples of how to apply the first law to psychometric processes, such as heating and cooling processes in HVAC systems. The lesson also highlights the importance of keeping track of the mass of different phases, especially when condensation takes place.

Video Highlights

02:40 - Explanation of how to calculate the amount of heat removed during a cooling process
04:04 - Explanation of how to calculate the amount of water that condenses during a psychometric process
09:16 - Explanation of how to apply the steady flow energy equation to a duct
22:56 - Example of a psychometric process involving the cooling and dehumidification of moist air

Key Takeaways

- Psychometric processes involve the application of the first law to both flow and non-flow processes.
- In these processes, moist air is treated as a mixture of two ideal gases - dry air and water vapor.
- The change in internal energy of dry air and water vapor is calculated assuming that air is a calorically perfect gas.
- The application of the first law to psychometric processes involves calculating the amount of heat removed during these processes.
- It's crucial to keep track of the mass of different phases, especially when condensation takes place.