Retrocommissioning is the application of the commissioning process to existing buildings. Retrocommissioning is a process that seeks to improve how building equipment and systems function together. Depending on the age of the building, retrocommissioning can often resolve problems that occurred during design or construction, or address problems that have developed throughout the building's life. In all, retrocommissioning improves a building's operations and maintenance (O&M) procedures to enhance overall building performance.
Retro-commissioning is a process to improve the efficiency of an existing building’s equipment and systems. It can often resolve problems that occurred during design or construction, or address problems that have developed throughout the building’s life as equipment has aged, or as building usage has changed. Retro-commissioning involves a systemic evaluation of opportunities to improve energy-using systems. If the same process were applied to a car, mechanics would make adjustments to the settings, controls, components and design of the engine based on how the owner actually drives.
Recommissioning is another type of commissioning that occurs when a building that has already been commissioned undergoes another commissioning process. The decision to recommission may be triggered by a change in building use or ownership, the onset of operational problems, or some other need. Ideally, a plan for recommissioning is established as part of a new building's original commissioning process or an existing building's retrocommissioning process.
Either application we use a variety of equipment and measures to complete each project. Depending on the scope of work projects will vary in amount of time to complete. Example: If we are hired to commission only one large piece of mechanical equipment, this process is less time. We need to gather data off the equipment. Such as amps, watts, voltage, run time, temperatures. This data will tell us how close to specs this device is operating when it was new.
To recommission a large building, depending on the size of the building could weeks. Smaller buildings generally take one week. However once we receive engineering drawing and all spec sheets of every piece of equipment in this building, this will provide us with a base line. Once all of our data and testing has been completed we can compare operational data. At this point we can provide ideas or suggestions on what needs to be replaced or added to increase efficiency.
The major challenges encountered by our retro-commissioning teams during the investigating phase are lack of or missing existing plans of the building systems, documentation of the building management system (direct digital control or pneumatic system), and submeters for utilities. The major steps during the investigating phase are understanding how building systems are currently operating; identifying deficiencies and potential improvements, and selecting the most cost effective “fixes” to implement; reviewing all aspects of the current operations and maintenance (O&M) program and practices; and reviewing user requirements that influence them. This includes interviewing building personnel, reviewing current O&M practices and service contracts, spot testing the equipment and controls, and trending or electronic data logging of pressures, temperatures, power, flows, and lighting levels and use. The investigation phase is generally the most time-consuming and expensive part of the retro-commissioning process.