Construction documents detail how control systems are to function and describe the components required to achieve the desired results. Included in these documents should be a detailed description of the scope of work, including expectations of the services of the various vendors and the communication among the various members of the construction team.

Control systems depend on feedback loops to achieve functional control. What our construction process needs is a similar mechanism — a type of feedback loop — when engineers hand off projects to contractors.

Prior to the preparation and submission of controls submittals, the engineer, owner, mechanical contractor, and controls contractor should meet to discuss what the documents require. The controls contractor should present his or her system, along with equipment and software to be utilized to achieve document requirements. During this meeting, the controls contractor's needs for clarification and/or additional information can be expressed to the engineer.

The suppliers of major components, such as chillers, packaged pumping systems, and self-contained units, specified with integral controls should participate in this meeting as well and confirm how the systems will interface.

The purpose of this pre-submittal meeting is to open lines of communication between all of the parties involved and confirm that the construction team fully understands the project requirements.

After project submittals are prepared, the team should meet again and review the control-system submittals in great enough detail to confirm that the project requirements are being met. During this meeting, the controls contractor should demonstrate the software tailored for the job.

The goal of each of these submittal meetings should be to focus the team on the project, facilitate communication, and set schedules and tasks to be accomplished during the construction process.

Commissioning has matured into a process that adds value to projects and confirms systems, including controls, are functioning as intended. Construction documents should describe what will be required during the completion of a project and turnover to the owner. The engineer or owner's commissioning agent should witness the “performance compliance” of the components and systems in cooperation with the test-and-balance and controls contractors.

The result of communication between engineers, owners, and contractors throughout the construction process is an improved feedback loop, as all parties are dependent on each other to achieve the best results.


A member of HPAC Engineering's Editorial Advisory Board, Kenneth E. Gill, PE, is director of mechanical engineering for and a vice president of James Johnston & Associates Inc. With more than 30 years of experience in HVAC engineering and consulting, he is a recipient of ASHRAE's Distinguished Service Award. He can be contacted at ken.gill@jjainc.com.

For previous Control Freaks columns or to visit the Networked Controls “microsite,” go to www.hpac.com.