The retro-commissioning included the
conversion of the building’s reheat valves from
pneumatic control to DDC control through the
installation of wireless thermostats and DDC
controllers.The intent of the retro-commissioning
• To inspect the systems and make recommendations
to fix problems and ensure that systems
are operating efficiently and in accordance with
the design intent.
• To identify opportunities to save energy in the
• To functionally test the equipment and systems
after all accepted repairs and energy conservation
measures are implemented.
The scope of work was planned in two phases.
Phase I was to conduct a thorough energy audit
and inspection of the building systems and
provide recommendations for repairs, upgrades
and modifications to the systems to enhance
performance and improve energy efficiency.
Phase II was to functionally test all of the systems
after the DDC conversion and after the system energy
conservation measures had been implemented.
Energy conservation measures included converting the
constant volume reheat system to a variable volume reheat,
installation of variable speed drives on the air handling
units, repair of energy recovery systems, tuning
control loops, and implementing economizer sequences
and time of day schedules. The results of the retro-commissioning
program are reflected in the chart below: