Psychrometric Calculator

Step-by-Step Guide to Using the Psychrometric Calculator

Introduction

The Psychrometric Calculator is designed to help you calculate various properties of air using inputs like temperature, humidity, and pressure. This guide will walk you through the process of using the calculator, outlining each step you need to take to obtain accurate results.

Step 1: Enter the Dry Bulb Temperature

Locate the Dry Bulb Temperature (°C) input field. Enter the current dry bulb temperature of the air, using a value between -40°C and 100°C. You can make precise inputs with increments as small as 0.1°C. Make sure this value is accurate as it is essential for further calculations.

Step 2: Enter the Relative Humidity

Find the Relative Humidity (%) input field. Enter the relative humidity percentage, which should be a number between 0% and 100%. This field accepts decimal precision up to 0.1% for more accurate input. Ensure the humidity input is correct to get precise results.

Step 3: Enter the Atmospheric Pressure

Next, enter the Atmospheric Pressure (kPa) in its designated input field. Provide a value in the range of 60 kPa to 120 kPa, with a step of 0.1 kPa for detailed measurements. Accurate atmospheric pressure is crucial for determining the correct properties of air.

Step 4: Calculate the Results

Once all input fields have been filled with their respective accurate values, the calculator will automatically derive several psychrometric properties. Here’s what each result field means:

• Saturation Pressure: The pressure at which water vapor is in thermodynamic equilibrium with its liquid, given as a value in kPa rounded to two decimal places.
• Partial Pressure: The partial pressure of water vapor in the air, computed from saturation pressure and relative humidity, displayed in kPa rounded to two decimals.
• Humidity Ratio: The mass of water vapor per unit mass of dry air, shown in kg/kg with four decimal place precision.
• Wet Bulb Temperature: A measure that reflects the temperature indicated by a thermometer covered in water-soaked fabric, with results rounded to one decimal in °C.
• Dew Point Temperature: The temperature at which air becomes saturated with moisture and dew can form, accurate to one decimal place in °C.
• Specific Volume: The volume occupied by a unit mass of dry air, given in m³/kg, rounded to three decimals.
• Enthalpy: The total heat content within the air at specified conditions, calculated in kJ/kg, shown with two decimal precision.

Final Thoughts

By accurately entering the required data, the Psychrometric Calculator efficiently calculates essential air properties necessary for various applications such as HVAC system design and meteorological studies. Ensure all inputs are within specified ranges for optimal results. If needed, recheck each step to confirm the values entered are accurate.