This blog series is focused on different methods to evaluate and reduce energy consumption of buildings. The demand for energy is increasing at an alarming rate and the building sector is one of the largest consumers of energy; gaining more and more prominence over the past few decades. Retro-commissioning is a proven process to help combat this problem. Let’s start with a quick overview of what building commissioning is.
Commissioning is a quality assurance process that provides documented confirmation that a building is operating at optimum level of the owner’s requirements. Commissioning ensures that building systems are planned, installed, tested, operated and maintained the way the owner intended. Commissioning often provides:
• Increased energy efficiency
• Maximized occupancy comfort
• Extended life cycle of equipment
• Reduces O&M costs
During the retro-commissioning process, existing building systems are inspected for physical, functional and performance conditions. All issues are documented and presented in a comprehensive report to the owner. Diagnostic test equipment is used to assess existing equipment efficiency and operating characteristics. This analysis is used to identify opportunities for energy conservation. The retro-commissioning process usually occurs in four distinct phases as illustrated below:
A research study on commissioning and retro-commissioning performed by Lawrence Berkeley National Laboratory in 2009 found that the average retro-commissioning project cost $0.30 per square foot with energy savings of 16% and with a simple payback of 1.1 years. Which brings us to the glaring question, why isn’t everyone doing this? Some possible reasons could be unfamiliarity with the retro-commissioning process and fear of any upfront costs. In order to overcome these hurdles, many cities across the nation are recognizing the importance of retro-commissioning/energy audits and are developing legislation that makes it a mandatory procedure. For example, New York City has developed PlaNYC, an agenda to meet energy challenges to building a greener, greater New York. Included in this plan is Local Law 84: Benchmarking and Local Law 87: Energy Audits and Retro-commissioning. In my next blog, I will discuss these laws in detail.
Do you have any questions regarding retro-commissioning? Drop me a line in the comments section below!