Heat Transfer and Relative Humidity — Lesson 2

This lesson covers the concept of heat transfer and relative humidity in the context of air flow through a duct. It explains how to calculate the rate of heat transfer and the relative humidity at the exit of the duct. The lesson uses a problem-solving approach to demonstrate the application of mass conservation and energy balance principles. For instance, it uses a problem where air enters a duct at 10° with 80% relative humidity and is steadily heated at a constant pressure of one bar. The lesson also explains how to use steam tables and formulas to solve the problem and how to represent the process on a chart.

Video Highlights

01:15 - Discussion on mass conservation and its implications
10:04 - Calculation of the rate of heat transfer
11:28 - Explanation of the concept of sensible heating
21:39 - Explanation of the energy conservation in the system
24:02 - Calculation of the amount of heat removed per kg per second of dry air

Key Takeaways

- Sensible heating refers to the process where no moisture is added or removed, and the specific humidity remains constant.
- The conservation of mass and energy are crucial concepts in understanding heat transfer in ducts.
- The rate of heat transfer and relative humidity at the exit can be calculated using specific formulas and steam tables.
- Accurate calculations and understanding of the properties of air and vapor are essential in solving problems related to heat transfer in ducts.