Recommissioning – a Practical Tool
Although the building industry, governments and utilities recognize the need to find significant energy savings, traditional approaches to decreasing energy use and improving the operation of buildings are leaving behind low cost and no cost...
Although the building industry, governments and utilities recognize the need to find significant energy savings, traditional approaches to decreasing energy use and improving the operation of buildings are leaving behind low cost and no cost opportunities.
Thanks to a new incentive program from Enbridge, several related points in the LEED Existing Buildings, Operations and Management (EB:O&M) rating system, and an expanding portfolio of successful case studies across North America, recommissioning is fast becoming the most practical, low-cost strategy for achieving immediate performance improvements.
It is therefore no surprise that Toronto’s Civic Action’s Race to Reduce – with over 50 million square feet of commercial office space signed up to reduce their energy costs by 10% by 2014 – is focusing on the recommissioning process as the weapon of choice to generate those savings.
What Recommissioning is Not
First let’s consider what recommissioning isn’t. It is not an energy audit where a consultant hunts for energy conservation strategies that are largely driven by capital-intensive measures (such as replacing all lighting with higher-efficiency bulbs and ballasts). Neither is it an RFP-driven process resulting in handing strategic control of your assets over to a third party. It is definitely not about selecting this year’s latest craze in retrofit technology and hoping that it’s the magic bullet for generating energy savings.
Focus on Right-Sizing
Instead, recommissioning is a holistic approach to comfort, energy, capital expenditure, operations and maintenance. It focuses on right-sizing the building’s mechanical and electrical systems and their operation for today’s conditions, not those in place when it was built. It examines key design calculations to determine that the oversized pump is not in fact necessary. It includes a utility analysis to highlight areas of energy and cost concern. It focuses on ensuring that equipment is doing what it was supposed to do, when it’s supposed to be doing it. It allows for updating fresh air volumes and revised sequences of operation according to current requirements. It tests and documents all key components and puts in place documentation and methodologies for ongoing monitoring and testing to ensure the building doesn’t drift once it’s running properly. It is a focused, low-cost approach to securing immediately that maddeningly oft-cited low hanging fruit that apparently is never quite within reach or even visible on the tree.
So What’s the Plan?
From an owner’s perspective one of the key aspects is that recommissioning is already a well-established four-phase methodology that puts the owner in charge of the process. It was enshrined by Portland Energy Conservation under a U.S. government-funded project and has been modified and adopted by the federal Government of Canada. The resulting Recommissioning Guide for Owners and Managers is a comprehensive step-by-step explanation that will present a path for your organization. See http://canmetenergy.nrcan.gc.ca/buildings-communities/energy-efficient%20buildings/optimization/recommissioning/1554
• Phase 1 – Planning. This is where the building owner or operator identifies the target building and develops the project scope. If you are looking to prioritize within a portfolio, once you’ve selected your candidate building (energy intensity? largest number of trouble calls?) you must define your project team, then determine what you are trying to achieve (improved comfort? generation of sorely lacking building documentation? energy conservation?).
In terms of building stock, the most successful projects have been for larger commercial office buildings – 50,000+ sq. ft. with a building automation system already in place.
• Phase 2 – Investigation. Your project team will then review the current documentation and begin diagnostic and witness testing of all key building systems. They will compare occupancy to existing schedules and generate a “Master List of Findings” which summarizes what can be done to save energy and resolve operational issues.
Note that simple fixes should be completed on the fly: this is not about documenting a business case for sign off by the Board nine months hence. If a damper link is broken, it can be fixed on the spot. A lighting control or air handling unit (AHU) schedule can be altered to reflect changed occupancy. As part of the investigation, the current capital expenditure program should also be reviewed – there’s no point recommending changes to a system scheduled for replacement in 18 months’ time.
Major areas for focus should be the elimination of unnecessary ventilation and simultaneous heating and cooling, and confirmation that the lighting control is both appropriate to the occupancy and is functioning as expected.
• Phase 3 – Implementation. This is about prioritizing items: complete work, commission, document, monitor, and communicate the changes.
• Phase 4 – Hand-Off Phase. This is a key point. Everyone involved needs to understand what has changed, where it’s documented and what the ongoing expectations are in terms of operations and maintenance. This is also the part where success is celebrated. The process needs a scheduled periodic repetition of testing – what is known as ongoing recommissioning – which is where the sustaining of savings comes in.
The Business Case
The Lawrence Berkeley National Laboratory in California completed a comprehensive review of 90.4 million square feet of recommissioned building space in 2004, subsequently updated in 2009. It identified typical energy savings of 16%, for an average payback of 1.1 years (Mills, Evan, Building Commissioning. LBNL, 2009). That’s a return on investment of 90.9%. Median costs were $0.30 per sq.ft.
Not surprisingly, the more energy intensive a building is (such as laboratories, hospitals, data centres, 24/7 offices), the greater the scope for finding savings opportunities where minimal or even zero investment can yield substantial savings.
And that’s not even beginning to account for the additional non-energy savings: reduced tenant complaint trouble calls, improved equipment life, and ongoing operational savings from having proper documentation in place. cce
Ian Sinclair, P.Eng., is manager of Existing Building Services at Enermodal Engineering/MMM Group, in Kitchener, Ont.
Investment of 54%
MMM Group and Enermodal Engineering are recommissioning over 4.5 million square feet of commercial office space in downtown Toronto on behalf of Oxford Properties. Encompassing six buildings and with an investment of $0.24 per square foot, the recommissioning has generated an average payback of 1.8 years, or an ROI of 54%. The upgrades are focusing on the existing building automation systems, eliminating off-hours usage and updating operational parameters to reflect current usage and standards as opposed to those that were in place at the time of construction.