Wet Bulb Dry Bulb Psychrometric Chart

Relative humidity dewpoint temp c.

Wet bulb dry bulb psychrometric chart.

Wet bulb temp c. The temperature read directly on an ordinary thermometer. When we know dry bulb temperature and wet bulb temperature. The psychrometric chart gives the relative humidity for a given wet bulb and dry bulb temperature.

When dry bulb and wet bulb temperatures of the air are known the dew point temperature can be plotted on the psychrometric chart fig. To use find the vertical line for the dry bulb temperature at the bottom of the chart and the slanted line for the wet bulb temperature at the curved top left edge. Dry bulb temp c. A process in which there is no change of dry bulb temperature.

By definition wet bulb temperature is the lowest temperature a portion of air can acquire by evaporative cooling only. The state of air with dry bulb temperature 75 o f and wet bulb temperature 62 5 o f can be visualized in the psychrometric chart as indicated below. Since this temperature is so commonly used assume that temperatures are dry bulb temperatures unless otherwise designated. Psychrometric chart includes so many axis which represent different parameters of air.

Two independent intensive properties are required to completely specify the state of air in the psychrometric chart. Properties of atmospheric air such as the dry bulb temperature the wet bulb temperature the dew point temperature the specific humidity the relative humidity specific enthalpy and specific volume are discussed in relation to the psychrometric chart below. By combining the dry bulb and wet bulb temperature in a psychrometric chart or mollier diagram the state of the humid air. The relative humidity is approximately 50 the humidity ratio is approximately 65 grains h2o lb dry air.

The higher its dew point temperature. It includes a dry bulb thermometer a wet bulb thermometer and a psychrometric chart a graph that plots the relationships between the dry and wet bulb temperature relative humidity and dew point at constant pressure. Altitude above sea level m. Now we are going to learn two of those axis dry bulb temperature and wet bulb temperature.

If the air is flowing. Example the state of air in the psychrometric chart. The wet bulb temperature is the temperature of an object that can be achieved through evaporative cooling assuming good air flow and that the ambient air temperature remains the same. Dry bulb temperature and 57 c wet bulb temperature experiences a temperature drop of 3 c as it passes through the 1 2 m wide stack of lumber.

Enter dry bulb temperature plus either wet bulb temp rh or dewpoint temp. Determine the properties of the air at state point 2 and compare them with those at state point 1.