Dynamic Psychrometric Chart

by AUROS Group

The AUROS360™ Dynamic Psychrometric Chart is an interactive graphical thermal comfort chart for trended & simulated data

Solution Overview

AUROS Group's integrated data monitoring and management platform provides a unique and secure way to display thermal comfort data by area(s) for all buildings in real-time using performance indicators, including dynamic simulation and targeted thermal comfort zones.

Thermal comfort is one of the most common occupant complaints in buildings. Common causes are drafty windows and envelopes, targeted radiant heat sources, and HVAC failures.  Most buildings are designed to create a uniform thermal environment that satisfies the majority of occupants.  Further, ASHRAE Standard 55 stipulates only 80% of your occupants need to be comfortable. The psychrometric chart is most useful during operations to identify if thermal comfort complaints are related to occupant sensitivities or building systems.

The dynamic psychrometric chart begins by plotting multiple data points representing temperature and humidity at a specific time interval and duration. We then overlay an area on the chart that indicates acceptable thermal comfort.  This comfort zone is defined as the range wherein occupants are satisfied with the surrounding thermal conditions.  After plotting the air conditions and overlaying the comfort zone, it is possible to see how passive design strategies can extend the comfort zone by mitigating the variability traditionally associated with indoor temperatures and humidity as a result of envelopes with air leakage.

Psychrometric charts are complex graphs used to assess the physical and thermodynamic properties of gas-vapour mixtures at a constant pressure. They are used to assess the properties of moist air, which is useful in the design of heating, ventilation, and air-conditioning systems for buildings. Dynamic psychrometric charts add thermal comfort zones to represent the range of conditions people find comfortable under different circumstances (such as summer and winter).

The chart is often used by mechanical engineers to dynamically plot points that represent the outdoor air conditions to better understand the treatment the air must go through to reach comfortable conditions for the occupants inside a building.  When using the psychrometric chart for this purpose, the plot points on the chart are shown simultaneously with other data, like indoor sensors, dynamic simulation, and historical data for temperature and humidity.

Solution Approach

Pittsburgh-headquartered Auros Group, with its AUROS360 Integrated Dashboard, created a unique Dynamic Psychrometric chart to analyze thermal comfort for both trended and simulated data.

AUROS360 is a software platform that optimizes and tracks building performance by continuously monitoring energy use and indoor environmental quality. The AUROS360 Integrated Dashboard, Dynamic Psychrometric Chart includes the following features and functionality:

·        A psychrometric analysis by plotting points then connecting them with process lines

·        A fully customizable psychrometric chart

·        Data plot including trended and simulation time-series data

·        Multiple plot data tags on single chart

·        Multiple thermal comfort zones for ASHRAE55 cooling and heating seasons

·        Time periods and time intervals customized for client use cases

·        Dynamic Psychrometric plots exported to image file

·        An unlimited number of simultaneous psychrometric chart analyses

·        Interactive charts to view items in greater or lesser detail


Solution Type

Energy Management, Environmental Compliance


  • Data Center
  • Facilities
  • Government
  • Hospital & Medical

Business Impacts

Optimize Processes, Improve Energy Efficiencies


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