What is continuous commissioning?
The term continuous commissioning was coined by engineers at Energy Systems Lab in Texas A&M University to describe the process of measuring energy use and environmental data on an ongoing basis to improve the operations of the building.
Typically buildings that have been retrofitted with various energy efficiency systems and improvements can be measured frequently (can be hourly, daily, weekly etc.) to verify that the systems performed as per design and thereby analyze the building’s energy performance. This data when combined with site visits and data collected from internal software was used to fine-tune the buildings’ operations. The result was a savings of nearly 30% on the annual building energy costs.
Below is the image of the savings from the continuous commissioning process at the A&M University in Texas.
Source: Whole Building Design Guide
There are various types of commissioning but while other commissioning processes focus on the building operations as per design continuous commissioning focuses on optimizing operations and control of various systems like HVAC based on the current building condition.
Hence continuous commissioning can be defined as a process whose main goal is to maintain an ongoing process to resolve operating issues, improve comfort, optimize energy use and identify areas of improvement (retrofits) for existing commercial and institutional buildings. During this process, a comprehensive evaluation is done on the systems in the building as well as the conditions within the building itself. These are based on the actual building conditions and current occupancy requirements.
Why you should adopt continuous commissioning?
Building owners, facility managers, energy management vendors and various other parties who deal with building energy efficiency and its operational efficiency face two major challenges:
- Knowledge barriers: Everyone involved in the operations of the building often find themselves faced with a variety of technologies that are always being upgraded or newly installed. This means that they have to keep upto date with their technical skills and expertise. Whenever there is an issue or the maintenance of a system arises, they sometimes rely on subcontractors or professional services to test and fix the system or equipment. In these cases, there is a loss of time and energy until the appropriate personnel address the issue or routine maintenance.
- Complexity of the building systems: When the building systems were first implemented in the 19030s, there were simple pneumatic controls. Since then, systems have come a long way in terms of digital controls or implementation of building management systems (BMS), building automation controls or IoT sensors.
Regular methods of commissioning will not be able to address these challenges since they are aimed at conducting their proceedings from time to time. In contrast, continuous commissioning uses ongoing stream of data from various systems of the buildings to monitor and recommend corrective action. This method produces savings not just when conducted but over many years in the future.
How IoT helps Continuous Commissioning:
A successful project includes monitoring data both at the building level as well as the component level. The high level building data is collected from meters and the granular information is gathered from sub-meters and sensors. Hence, IoT (Internet of things) plays a very important role in continuous commissioning. IoT helps by providing the granular data from its sensors, cloud based information as well as advanced capabilities like analysis of historical data as well as predictive analytics.
Calculations of real energy savings are only possible by comparing the historical energy consumption data with the post consumption data to reveal insights and savings derived from this method. The baseline needs reliable data to analyze and as a result, measuring energy and environmental data should be done in proper and meticulous way. This step could be critical because the evaluation of possible energy efficiency solutions are based on this data and could have an impact in the business decision-making.
IoT allows the implementation of sensors on all systems, equipment and even rooms inside the building. This way the energy consumption can be tracked for each system like the HVAC, lighting, heating, cooling, indoor temperature, luminosity, humidity, CO2 levels as well as occupancy of rooms. Apart from using this data for continuous commissioning you can also use it for 1.Billing individual tenants 2.load forecasting 3.managing energy as per the energy prices and 4.forecasting with the use of predictive analytics.
Implementing Continuous Commissioning
Continuous Commissioning typically has a two-phase approach. In the first phase the goals of the project as well as estimated potential savings are identified. In the second phase, the actual implementation process takes place. Activities such as establishment of baselines, integration with existing systems to continuously monitor data, recommendation and implementation of specific measures for potential energy savings as well as training and documentation are conducted.
Continuous commissioning establishes data-streaming as quickly as possible in the project. It also established connection to the building management systems as well as the IoT systems. Some of the data collected are control signals (e.g., if equipment is on or off), sensor readings such as pressure, outside and indoor air temperature, humidity, equipment status such as if damper is open or the value position and the actual energy consumed in terms of kW.
Some of the potential savings opportunities that are recommended and implemented as part of continuous commission are:
- Malfunctioning or poorly calibrated equipment
- Operational changes (i.e. equipment scheduling, equipment set points, behavioral changes).
- Low cost repairs such as leaking ducts, valves or installing actuators
- Optimize equipment setting such as chilling scheduling, air or static pressure resets.
- Small cost based corrective actions such as installation of a framed filter for reduced static pressure, installation of isolation dampers etc.
The team typically consists of the professional services project manager, in-house technicians and engineers that would help with the implementation.
Deliverables include documentation, project plan, maintenance recommendations, existing systems conditions report, list of malfunctioning equipment, list of disabled controls, existing controls and set points, and improved controls and operation sequences.
Buildings typically see savings around 11-20% of the energy data collected through this process. This is a considerable amount of savings for any building operator and hence they usually are sold on proceeding with this methodology.
According to a ACEEE Summer Study on Energy Efficiency in Buildings, the table below indicates a wide range of opportunities in different settings.
Continuous commissioning is an ongoing process to evaluate a building’s energy performance based on continuous monitoring of data from baseline to operating. It is an effective approach to resolve operating issues, improve occupants’ comfort levels, optimize performance for commercial buildings. Since this approach focuses on the system controls and operations, it uncovers savings opportunities over the life of the project, which typically runs for more than a year when compared to other commissioning processes.
These savings can be realized in conjunction with systems like building management systems and IoT applications that utilize sensors and data on the cloud. This is because energy consumption data from monitoring a data-stream is effective in continuous commissioning. Savings as high as 20% can be realized in energy costs and hence it is best to adopt continuous commissioning when you are looking to meet your annual energy goals.