Psychometric Chart Calculations — Lesson 6

This lesson covers the practical application of psychometric chart calculations in HVAC (Heating, Ventilation, and Air Conditioning) systems. It explains how to locate states on a psychometric chart, retrieve values, and perform calculations for different HVAC scenarios. The lesson also demonstrates how to use the psychometric chart to simplify calculations, making it easier to evaluate the mass flow rate of dry air, mass balance of water, and heat transfer in HVAC systems. For instance, the lesson discusses a scenario where air is first cooled and dehumidified, then heated to achieve a comfortable temperature and relative humidity.

Video Highlights

01:14 - Locating the state on a psychometric chart
03:19 - Explanation of how the psychometric chart simplifies calculations
08:08 - Calculating mass flow rate of dry air
13:51 - Calculating mass flow rate for unit volume flow rate of air
15:16 - Calculating the amount of heat added in the heating section

Key Takeaways

- A psychometric chart simplifies calculations in HVAC applications by providing ready-to-use information.
- Two properties or quantities are needed to locate a state on a psychometric chart.
- The psychometric chart embeds all the intermediate steps, making it straightforward to use.
- The use of a psychometric chart may compromise accuracy slightly due to approximations and visual interpolations.
- Psychometry is not limited to HVAC applications; it has various practical applications where heat measurement is crucial.