
It is fairly common for these lines to be indicated in intervals of ten. These lines are curved, and begin at 100% along the top of the chart, and decrease moving downward.

Wet bulb temperature lines on a psychrometric chartĪnother feature indicated on every psychrometric chart is relative humidity lines. These lines are indicated at diagonals, and like dry bulb temperatures they increase from left to right.
#ASHRAE PSYCHROMETRIC CHART REGISTRATION HOW TO#
This module will provide you with an understanding of simple psychrometric charts and how to use. This online eLearning program has been made available through a cooperative venture between ASHRAE and NEBB.

Air temperature increases from left to right.ĭry bulb temperature lines on a psychrometric chartĮvery psychrometric chart also includes wet bulb temperatures. Individuals have a 12-month access to the online courses once they register. When using the psychrometric chart for this purpose the data points move around the chart.Įvery psychrometric chart includes vertical lines that represent the dry bulb temperatures. The chart is also often used by mechanical engineers to dynamically plot points that represent the exterior air conditions and understand the process the air must go through to reach comfortable conditions for the occupants inside a building. This psychrometric chart was generated using Climate Consultant. In this chart, the dark blue boxes represent the comfort zone, and the other colors represent design strategies that have been enabled to study how they can potentially expand the comfort zone. After plotting the air conditions and overlaying the comfort zone, it becomes possible to see how passive design strategies can extend the comfort zone.Įxample of how plotted data on a psychrometric chart can be studied, and related to passive design. Then, overlaying an area that identifies the “comfort zone.” The comfort zone is defined as the range within occupants are satisfied with the surrounding thermal conditions. The first is done by plotting multiple data points, that represent the air conditions at a specific time, on the chart. Psychrometric processes include physical and thermodynamic properties such as dry bulb temperature, wet bulb temperature, humidity, enthalpy, and air density.Ī psychrometric chart can be used in two different ways. humidity, and can be used to express human thermal comfort, design strategies, and energy requirements for those strategies.Ī psychrometric chart is a graphical representation of the psychrometric processes of air.

Psychrometric charts show temperature vs. While they may seem overwhelming at first, by learning how the variables interact, you can begin to use the psychrometric chart to interpret occupant comfort and effective passive design strategies for your location. A psychrometric chart for a given location can tell you information about temperature (wet bulb and dry bulb) and humidity (relative and absolute).
