Psychrometric Calculator
Psychrometric calculations are essential for understanding the properties of moist air, which are crucial in various applications such as HVAC systems, industrial processes, and environmental control. These calculations typically involve parameters like dry bulb temperature, wet bulb temperature, humidity ratio, relative humidity, and enthalpy. Here’s a basic overview of these parameters and how they can be organized in a table.
Key Psychrometric Parameters
- Dry Bulb Temperature (DBT): The temperature of air measured by a regular thermometer.
- Wet Bulb Temperature (WBT): The lowest temperature that can be reached under current ambient conditions by the evaporation of water only.
- Humidity Ratio (HR): The mass of water vapor per unit mass of dry air, usually expressed in grams per kilogram (g/kg).
- Relative Humidity (RH): The ratio of the current absolute humidity to the highest possible absolute humidity (which depends on the current air temperature), expressed as a percentage.
- Enthalpy (H): The total heat content of the air, including both sensible and latent heat, measured in kilojoules per kilogram (kJ/kg).
Sample Psychrometric Table
Below is a sample psychrometric table that illustrates these parameters at different conditions:
| Dry Bulb Temp (°C) | Wet Bulb Temp (°C) | Humidity Ratio (g/kg) | Relative Humidity (%) | Enthalpy (kJ/kg) |
|---|---|---|---|---|
| 20 | 15 | 10.5 | 60 | 50 |
| 25 | 18 | 12.8 | 70 | 60 |
| 30 | 22 | 15.5 | 80 | 70 |
| 35 | 26 | 18.2 | 90 | 80 |
These values are illustrative and would typically be calculated using psychrometric equations or derived from a psychrometric chart, which graphically represents these relationships1.
Understanding Psychrometric Charts
A psychrometric chart is a graphical representation of the physical and thermal properties of moist air. It allows users to visualize relationships between different psychrometric parameters and is widely used in HVAC design and environmental control. By plotting any two known values on the chart, other properties can be determined14.Psychrometric calculations are crucial for designing efficient ventilation systems, ensuring thermal comfort in buildings, and optimizing industrial processes where air moisture content is critical7.