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FY16 RCx (Completed)

Description

In FY16, the Retrocommissioning teams completed six buildings.  

Background

Activities & Recreation Center

Most air-handling units were scheduled to turn off during unoccupied hours, reducing consumption from the previous operation of running 24 hours daily. Programming changes were made to fix the issues and optimize the air handling units. Occupancy sensors were installed in several areas of the building including the multi-purpose rooms. Demand control ventilation was implemented to manage outside air intake depending on the space CO2 levels. Infiltration through the building envelope has been reduced greatly by improving building pressurization (by better control of exhaust fans). There are three air-handling units serving the East Gymnasium/Basketball court area; now only one AHU runs most times to provide the necessary space conditioning and the other two units comes on when necessary. Advanced Computation Building All four air handling units serving the data center were running full speed. The computer load reduced significantly after PetaScale became operational and four units are not necessary to condition the space. The units were reprogrammed to run only two them at a time at minimum speed (25% fan speed). There is also a rotation schedule in place so that all units get an appropriate same amount of run time. To improve other areas of the building there were repairs made on AHU 8, including VFD’s, damper controls, the mixing chamber, and economizer cycle was put back into operation. A faulty humidity sensor was also fixed. The set points for the mechanical room air handling unit (AHU2) was modified (Heating - 60F, Cooling - 85F) and the hours of operation have considerably reduced. On the third floor occupancy schedules were added and the Liebert units were retired. Found sewer surcharging problems and added a back water valve. East end of mechanical room was flooding several times a year previously. Note: The computer load in the space has been increasing in the past year. This has increased the electrical load on the building recently. Davenport Hall Most air handling units were connected to the campus chilled water. There were two chillers in the building serving few air handling units (AHUs 1, 2, 20). They were retired and all air handling units are now connected to the campus chilled water loop. New DDC controls were added to the air handling units to control fan, dampers and valves. New VFD were installed for AHU5. Air balance was performed on spaces and air flows were reduced wherever possible. The air handling units were running 24/7 previously and occupancy schedules were implemented to shut off the non-lab units when the building is unoccupied. Occupancy sensors were installed for classrooms served by AHU13 to control lights and shut off AHU when all spaces are unoccupied. AHU12 was scheduled off permanently and an override switch was installed in the suite so that the air handling unit can be turned on when required to provide cooling. English Building New controls were added to the make-up air unit, exhaust fans and the condenser water system steam heating exchanger valves. DDC thermostats were installed on heat pumps serving classrooms with occupancy sensors to enable set back during unoccupied periods. The old chilled water change-over relay is now used to shut all heat pumps in the building and can be turned off through DDC. So, the entire heat pump system is now scheduled to turn off during unoccupied periods. The time clock for AHU2 serving the student admissions/advisory office was fixed and scheduled to turn off during unoccupied periods. The heat exchanger and pump associated with AHU2 was also tied to the timeclock. Swanlund Administration Building The air handling units were running 24/7 previously and occupancy schedules were implemented to shut off the units when the building is unoccupied. The kitchen and restroom exhaust fans were connected to the Siemens system to enable shutting them off during unoccupied periods. The five exhaust fans in penthouse mechanical room serving the conference rooms and offices were decommissioned to avoid exhausting air from conference rooms. Connected the restroom and/or kitchen exhaust fans to the Siemens system and scheduled to shut off when the building is unoccupied. The hot-water boilers were not firing properly, so the amount of combustion air into the boiler room was increased per manufacturer’s recommendations.  Transportation Building The chiller in the south-east corner of the building serving AHU3 was retired and the unit was connected to the campus chilled water loop. The time-clock for AHU3 was fixed and the unit is now scheduled during unoccupied periods. The occupancy sensors in the areas served by AHU1 controlled only lights. Those sensors were replaced with new sensor with an extra set of contacts that is now used to shut down VAV boxes when the space is unoccupied. The air handling units were running continuously; the units are now scheduled to turn off during unoccupied periods. The basement occupants were experiencing cold air drafts because the rooms have floor air grills right beside their workspace and had more airflow than required. Dampers were installed in the floor grills and fan speed reduced to reduce the air flow and cold air drafts. There were separate thermostats controlling heat pumps and radiators in the classrooms causing simultaneous heating and cooling especially in winter months. They are now replaced with a single thermostat controlling both heat pumps and steam radiators. Occupancy sensors were installed in spaces with DX units and heat pumps to control both lights and air conditioning units.

 

Conclusion

  • Activities & Recreation Center, 36% savings
  • Advanced Computation Building, 4% savings
  • Davenport Hall, 39% savings
  • English Building, -5% savings = 5% increase
  • Swanlund Administration Building, 32% savings
  • Transportation Building, 31% savings

Project Team

  • Project Leader:

    Karl Helmink

Themes

Project Location(s)

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