Retrocommissioning — a process that identifies no- and low-cost energy efficiency improvements in existing buildings — is key to lower operating costs and improved building performance, according to McGuire Engineers president William J. Stangeland.
Energy savings can range from 11 to 72 cents per square foot.
In an article for HPAC Engineering, Stangeland says his company has worked on retrocommissioning projects for a major museum in Chicago and a large community school in Wisconsin.
McGuire Engineers studied the chilled water system to cut energy use at the museum, which cooled, heated and humidified more than 1 million square feet of space to tight tolerances year-round.
Through modifications of air-handling units, the hot-water-piping system, and sequence of operations and the integration of temperature/carbon-dioxide sensors in classrooms, the community school reduced its energy use and improved occupant comfort.
Retrocommissioning should target the building envelope to reduce energy waste from openings to the outside that are not sealed tightly. The process should also look at energy management systems, operational controls and equipment that are not working or programmed correctly.
Stangeland says a good way to start retrocommissioning is to perform an energy audit or document the building’s Energy Star rating. Next steps include:
- Developing a plan with the present-day requirements of the building and its systems, and identifying operational problems and any other low- or not-cost measures to implement.
- Testing all building systems to confirm proper operation or to determine needed work.
- Implementing and documenting tasks in the plan.
- Repairing and/or upgrading deficient systems.
- Retesting all building components after changes are made.
Businesses across the UK could save more than £3.7 billion ($5.6 billion) annually by investing in energy-efficient equipment, according to research published by the Energy Efficiency Financing scheme earlier this month.
Some 35,000 buildings that used the Energy Star Portfolio Manager tool to track and manage energy use between 2008 and 2011 realized an average annual savings of 2.4 percent with a total savings of 7 percent, according to EPA.