Trends in Green
The Benefits of Retro-Commissioning
- By Dillon Mitchell
- December 1st, 2015
New Year’s resolutions are a rite of passage for millions of people. We look back to reflect on changes during the past year, and we set goals for improvement. Through a process called retro-commissioning, the same approach can be used to lower operating costs and improve occupant satisfaction in your school buildings.
What is retro-commissioning? Think of it as a set of New Year’s resolutions for your facilities. In new school buildings, commissioning procedures make sure systems are operating correctly before the facility is occupied. Retro-commissioning is the same type of process, but for existing buildings. You set goals for system efficiency and indoor environmental quality, measure how your building is currently performing and then start making improvements.
When To Retro-Commission
In general, it is a good idea to retro-commission your school facilities every ten years. The reason is simple: buildings change over time. Enrollments rise and fall. Evolving educational needs cause rooms to be repurposed. Systems begin to operate less efficiently. In this context, retro-commissioning becomes a tool for aligning your facilities to meet the needs of your current mission. If a room was designed with ventilation based on five occupants, but has since become a classroom holding 25 students, changes need to occur.
Another good time to retro-commission is when operating costs unexpectedly rise, or when teachers and students begin to complain about environmental issues. It is amazing what a systems analysis may uncover. In one building with airflow issues, we found that two rooftop air handling units with the same size footprint, but with different capacities, were installed in place of one another. As a result, one unit was drastically undersized to serve its portion of the building, while the other unit was oversized. From a labor and cost standpoint, the problem was easy to fix. But it was only uncovered after a process of analysis and investigation.
Reaching for Higher Fruit
When retro-commissioning is mentioned, many owners immediately think of guaranteed energy savings contracts. But retro-commissioning can go far beyond targeting simplified approaches such as lighting replacements. By working with a commissioning agent to co-define goals, not guarantees, school administrators are better able to holistically address their needs and measure positive results.
For example, a retro-commissioning process may uncover a spike in classroom plug loads. Upon further investigation, it is common to find that teachers are bringing mini-fridges or even hot plates into the classroom. This is an energy use issue, but it is also a teacher satisfaction problem. Perhaps the teacher lounge is undersized or not equipped with enough microwaves or refrigerators. In a traditional guaranteed Return on Investment process, your professionals will most likely stop after identifying the plug load issue. But by conducting a holistic assessment and targeting the root cause, you are able to achieve goals such as, “Make our teachers more satisfied and productive.”
Retro-commissioning doesn’t need to only involve mechanical and electrical systems. Windows, wall construction and roofing systems are prime candidates for analysis. Anything that can be measured can be improved and verified.
Just like that first trip to the gym, getting started is the hardest part of retro-commissioning. Before you begin, it is important to have specific goals. Often, the retro-commissioning of an entire building yields too much information to absorb all at once. For many school districts, it is better to target specific areas, such as improving indoor air quality or lowering operating costs related to plug loads.
Because retro-commissioning is a relatively new concept, professional services firms have a wide range of standards and methods. Finding the one that is right for you can take time. Try to identify a partner with a minimum of 20 years’ experience in long-term building care, as well as specialized expertise with digital controls and indoor environment quality.
Achieving Your Goals
Every school community is interested in better buildings, lower operating costs and happy teachers and students. These are all benefits that a retro-commissioning process can provide. Yet like that New Year’s resolution, the path to success requires setting achievable goals and committing to a plan for continuous improvement. With the right process and the right tools, 2016 can be a year of amazing possibilities for your facilities and your community.
This article originally appeared in the December 2015 issue of School Planning & Management.
Dillon Mitchell, PE, LEED-GA, firstname.lastname@example.org, is Electrical Engineering Discipline director for Fanning Howey.