Continuous Optimization


There are certain fundamental tasks that are common to Re-Commissioning or Retro-Commissioning an existing building’s systems.


These tasks are as follows:

  • Gain a detailed understanding of the building HVAC systems. Request copies of architectural, mechanical and electrical drawings (.dwg and/or .pdf files).
  • Review mechanical operation and maintenance manual(s) . Make copies of equipment shop drawings, test and balancing reports, and temperature control drawings.
  • Review electrical distribution system single line diagram and motor schedules.
  • Colour code the ductwork for the supply, return and exhaust air systems.
  • Print 8 1/2 x 11 or 11 x 17 floor plans and colour code areas served by different hvac systems.
  • Review the testing and balancing reports.
  • Prepare an excel spreadsheet summarizing the HVAC systems, areas served, type of HVAC system, airflow, static pressure, motor HP, VSD or not, schedule of operation.
  • Review the temperature controls drawings and control sequences of operation.
  • Conduct a preliminary site survey to get a “feel” for the building and its systems.
  • Interview the building operator (if there is one) and discuss the system operation. Gain an understanding of the building operator’s perspective on how the systems are performing and where the greatest need(s) of RE-Cx exist.
  • Interview building occupants (preferably Department Managers).
  • Ask occupants for their perspective on occupant comfort; too hot, too cold, just right, too humid, too dry, just right, drafty.
  • Do these perceptions change throughout the day from morning to noon to afternoon to evening?
  • Are there seasonal differences in these perceptions? (spring, summer, fall, winter). Analyze data gathered from building operator and building occupant interviews as if the data were pieces of a large puzzle. Place the pieces of the puzzle on the table metaphorically speaking.
  • Move the pieces around; what picture begins to emerge?
  • Based upon a technical understanding of how the building is supposed to operate; what is the picture supposed to look like? What pieces are missing? How do you locate these pieces?
  • Conduct detailed site survey to verify equipment motor HP and equipment schedules, etc.
  • Request permission to load a copy of the temperature controls Building Automation System (BAS) software on your laptop. Acquire security key if necessary and any interface devices required to “talk” to the system.
  • Learn the programming language and review all sequences of operation programmed into the system.
  • Compare the programmed sequences of operation to those written for the project. Have the sequences been coded properly? Dialogue with DDC contractor as required.
  • Prepare trend logs for all important equipment operation. Example. Boiler control, chiller control, VAV box control, AHU chilled water valve control, heating water valve control, economizer control. Analyze trend logs for cause and effect.
  • Identify operational issues and opportunity for improvement.