Whole-Building Diagnostician Software R&D

On this page you'll find information about the U.S. Department of Energy's whole-building diagnostician software research and development project.

Project Collaborators

Pacific Northwest National Laboratory (PNNL), Honeywell Technology Center, and University of Colorado


The Whole-Building Diagnostician is a modular diagnostic software system that provides detection and diagnosis of common problems associated with the operation of heating, ventilating, and air-conditioning (HVAC) systems and equipment. In partnership with industry, DOE works to accelerate the transfer of building diagnostic technology into practice.


The Whole-Building Diagnostician software includes two modules. The Whole-Building Energy (WBE) module tracks overall building energy use and alerts the operator when unexpected changes in consumption occur. Future versions of this module will assist the operator in isolating and correcting the causes of these undesirable changes in consumption.

The second module, the Outdoor Air/Economizer (OAE) module, monitors the performance of the air-handling units and detects problems with outside air control. The current version detects about 20 different basic operation problems. The system uses color coding to alert the operator when problems occur, and then provides assistance in identifying the causes and advice for correcting them.