The Sustainable Campus (Trends and Innovations)
Recalibrate, Retune, Rebalance
- By William Wright, Joe Monahan
- June 1st, 2016
When some students in a building are
wearing jackets to stay warm and others are
wearing shorts to stay cool, it is time for retrocommissioning.
Commissioning new construction ensures that
building systems are functioning as designed for a planned use;
retro- or recommissioning retools older building systems while
optimizing design conditions based on actual use. The goals are
user comfort, right-sizing flows for actual use, energy efficiency
and cost savings.
Catalyst for Growth
In Glassboro, NJ, Rowan University’s new $70.6 million engineering
building already was under construction when it became
clear that the 1996-built Rowan Hall needed a tune-up. The landmark
structure for the Henry M. Rowan College of Engineering,
Rowan Hall is occupied by 600 students, faculty and staff, morning
to night, every day of the week. Designed by Ballinger nearly
20 years ago, the elegant building on a pond is home to multiple
engineering disciplines, including biomedical, chemical, civil and
environmental, mechanical, and electrical and computer engineering.
It is the 99,349-square-foot tribute to the philanthropist
whose generosity created the College of Engineering and served as
the catalyst for the growth of the entire university.
Since the building opened, the engineering enrollment at the
university has doubled, increasing stress to the building systems
every year. At times it was uncomfortable to work there, and end
users complained of temperature, humidity and airflow problems.
This is not unusual. System controls in every building need to be
recalibrated over time. Controls drift out of calibration, wires get
snipped, dampers bind, airflow stations become dirty, devices or
logic get bypassed, new equipment overloads the system, fume
hoods are added, and doubling the number of users can certainly
impact how well airflow is transmitted.
Research and laboratory buildings in particular need to have
HVAC systems in good working order and should be recommissioned
ongoing with comprehensive calibration every five
years. The Rowan recommissioning project began with certified
balancing professionals who took readings of the current air flows/water throughout the building to establish a baseline of as-found
readings. Labs have a significant amount of ventilation air brought
in and contaminated air exhausted out through fume hoods and
other devices. Critical to the safety of users, fume hoods are also
required to be recertified annually.
Even classrooms and lab spaces without fume hoods may have
tight positive or negative pressure requirements, and flow stations
and static pressure sensors can malfunction if they become dirty
or clogged. Since they are indispensable to the operation of the
HVAC systems, annual checking and recalibrating is required.
The next phase is to recalculate the building’s loads based on
actual use. Buildings are designed for a certain occupancy and
program, but both change over time and the building systems
don’t always keep up with the modifications. There are more
people using Rowan Hall now than when it was constructed, and
the machines and equipment have changed.
Once the load study and air change rates have been identified,
a professional engineer will redirect the systems to obtain the correct
flows, and the facility will be rebalanced and recommissioned.
The university may ultimately need to invest in new control sensors
or other components, but they are likely to be of better quality
today than when the building was built. Overall, the cost savings
will far outweigh the cost of new technology.
As part of the project, an independent commissioning firm
will evaluate, test and correct the existing HVAC control systems
and components to meet current facility requirements, optimize
function and energy efficiency and improve comfort. This process
involves investigation, analysis and corrective action of the building
A building like Rowan Hall is very energy-intensive, so the
savings may be realized very quickly after recommissioning. As
with Rowan Hall, the university’s Science Building had airflow and
temperature issues a few years ago. Recommissioning reduced the
energy consumption in that building by 40 percent and eliminated
Whatever the building program, system equipment and
controls are constantly changing, some at a more accelerated pace
than others. After two to three years, every building has drifted or
changed to the point where a recommissioning effort will result in
cost savings and improved comfort and operation.
This article originally appeared in the June 2016 issue of College Planning & Management.
William Wright is the president of Wright Commissioning, based in Philadelphia.
Joe Monahan is the assistant vice president for Planning & Construction at Rowan University.