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FY14 RCx (Completed)

Description

In FY14, the Retrocommissioning teams completed ten buildings.  

Background

Business Instructional Facility

Low VOC adhesive on armaflex insulation caused splitting, so these were repaired using armaflex tape. Steam leaks through poor gaskets were repaired at the steam entrance and insulation was replaced. Door seals and sweeps were added to doors to prevent air migration and maintain humidity levels. Unnecessary mechanical room exhaust fans were turned off, seeing as they had been exhausting conditioned air and making the room negative. Additional leaks in the building envelope will be addressed by an architectural consultant. Many VAV temperature sensors were reinstalled due to poor initial installation. Temperature and humidity sensors for all equipment were tested and recalibrated if necessary. Ventilation rates and schedules were adjusted in an attempt to prevent windows in classrooms from being opened. Tighter space temperature control was programmed throughout the building.

David Kinley Hall

The air handling units (AHUs) providing air conditioning to the basement and auditorium were maintaining space conditions 24/7/365. With the addition of DDC controls, schedules will be implemented to shut units off and set back airflows during low and no occupancy times. The primary energy conservation method on the units serving the first through fourth floors was scheduling tighter setbacks and reducing CFM during non occupied times via occupancy sensors. All temperature transmitters and sensors on all six air handling units were calibrated. The energy recovery wheels were investigated and programming was modified to increase their effectiveness. The airflow monitoring stations were verified and calibrated as needed to ensure proper building ventilation. Metal diverting plates that had broke loose and adhered airflow were removed, therefore fixing the vibration noise issues and helping airflow to those affected spaces served by AHU2. There are 77 VAV boxes in the building. Each box was inspected for proper operation and calibrated. Also, to assist with maintenance in the future, all VAVs were labeled in the attic with their names in programming and which room(s) the box supplies, while labels were also put in the attic to indicate locations of remote VAV boxes.

Gregory Hall

The air handling units (AHUs) providing air conditioning were maintaining space conditions in offices and labs 24/7/365. The primary energy conservation method was scheduling setbacks and reducing CFM during non occupied times via occupancy sensors. The first issue recognized by the team was the extreme variation in pressure of the building. There was one of four chimneys in the attic open to the outside allowing unnecessary exhaust through the attic. This issue was magnified by open chases between the basement and attic with open exhaust ducts in these areas allowing return air a very easy path to the outside. Occupancy sensors were connected to the VAV boxes in classrooms, larger offices and conference rooms to maximize savings, while the remaining sensors only control the lighting as per original design. This will reduce the CFM output of the AHUs when spaces go into unoccupied mode during a normal occupied time. There are ~150 VAV boxes in the building. Each box and thermostat was inspected for proper operation and calibrated. Discharge temperature sensors were also checked during this process. There were offsets put in for many of these CFM readings to read the actual airflow through the box, allowing AHU3 to meet static set point for the first time since installation in 2009.

Krannert Art Museum

The air handling units (AHUs) providing air conditioning were maintaining space conditions in the space 24/7/365. The primary energy conservation method was scheduling setbacks and reducing CFM during non occupied times. The constant volume systems were modified to be VAV systems. The airflow modulates up and down to maintain space temperature and humidity setpoints. A building exhaust fan was shut down during unoccupied hours. Even with the completion of the new project, we found several things that needed attention. The humidifiers had broken floats, one of the dew points sensors needed to be repaired, loose wiring connections were found causing control valves to act erratically. Ductwork revisions were completed by the contractor. We helped coordinate the division of responsibility document going forward. Air handler ASU-3 had significant work performed with it. We retired the remaining MACS in the building and installed new VFD’s on this unit as well as new DDC controls. Drain pan problems were corrected as well as a leaky humidifier. The heat exchanger and pumps in this room needed attention also.

Freer Hall

The air handling units (AHUs) providing air conditioning were maintaining space conditions in offices and labs 24/7/365. The primary energy conservation method was scheduling setbacks and reducing CFM during non occupied times. The first issue recognized by the team was the extreme negative pressure of the building. Upon further investigation, it was determined the chimneys were previously used as exhaust for toilet rooms and old locker rooms that no longer require this exhaust. Therefore a project has been funded to permanently cap the chimneys at the top to keep unnecessary exhausting of conditioned air 24/7/365. Occupancy sensors were installed in the labs, offices and conference rooms in the north basement and south 3rd floor of the building, which controls the lighting and variable air volume boxes (VAV) for the spaces. This will reduce the CFM output of the AHUs when spaces go into unoccupied mode during a normal occupied time. There are 28 VAV boxes in the building. Each box and thermostat was inspected for proper operation and calibrated. Discharge temperature sensors were installed after all the reheat coils for monitoring leaking reheat valves on the third floor (20 VAV’s) only. There were offsets put in for many of these temp sensors to read the actual temperature.

Material Sciences and Engineering

VFDs for AHU4 supply, return, & exhaust fans and htg pumps were added. Steam and condensate lines were insulated. Occupancy sensors in labs were installed in order to reduce the exhaust from fume hoods. System fluid for the reheat loop was replaced and the perimeter heating system (glycol system) was readjusted due to bad chemistry and dirty water. Transducers were replaced. Air handler control panels were rebuilt. Roof vents were closed to save energy. Outside air dampers for AHU1 were fixed. The Ebtron AFMs on AHU2 were fixed. Override timers were placed in lecture halls to permit temperature control outside of regular hours. Their time clocks were also repaired. Freeze stats were added to AHU1. Abandoned exhaust systems were capped. An outside air economizer feature was added to AHU2. VAV boxes were fixed and adjusted. AHU1 and AHU2 will now discharge relief air to the building rather than outdoors to save energy and make the building more comfortable. The AHU3 and AHU5 DX direct expansion cooling units will be replaced with chilled water units. Remote DPTs were installed in both htg loops and chilled water loops. All unused fume hood exhausts were sealed. We recommend turning off fume hoods when not in use by consolidating chemicals in one fume hood or vented storage cabinets.

Admissions and Records

The air handling units (AHUs) providing air conditioning were maintaining space conditions in offices and classrooms 24/7/365. The primary energy conservation method was scheduling the AHUs off during non occupied hours. Minimum outside air dampers were also added to both AHUs to save energy and improve comfort during summer months. To maintain comfort conditions, all thermostats were calibrated and/or replaced and the heating valves were inspected for proper operation. There are approximately 49 VAV’s in the building. They were all inspected for proper operation and were calibrated and balanced which allowed for the reduction of air to the spaces, resulting in fan energy savings without compromising comfort. Pneumatic tubing was cracked and leaking to a majority of of VAV boxes and finned tube radiators, which were subsequently replaced.

Art and Design

The air handling units (AHUs) providing air conditioning were maintaining space conditions in offices and classrooms 24/7/365. The primary energy conservation method was scheduling the AHUs off during non occupied hours. To improve comfort, all thermostats and temperature sensors were calibrated and / or replaced and the heating and cooling valves were inspected for proper operation. The AHUs were all inspected for proper operation and were calibrated and balanced which provides better space pressurization and energy savings while improving comfort. Two new restroom exhaust fans were installed and are automated. Sources of outside air infiltration such as abandoned exhaust ducts and grilles were eliminated to better control temperature and humidity in the building.

Temple Hoyne Buell Hall

The air handling units (AHUs) providing air conditioning were maintaining space conditions in offices and studios based on an agreed upon schedule, but were only setting the fans to a min, not shutting them off. The primary energy conservation method was scheduling tighter setbacks and reducing CFM during non occupied times via occupancy sensors (still being designed as of Jan 2014). The first issue recognized by the team was the excess ventilation in the stairwells. There was one thermostat controlling a makeup fan and outside air damper on a call for cooling, as well as controlling a unit heater on a call for heat. These fans would turn on during most summer days and not shut off for days due to a bad design. We took these fans out of operation and added magnetic door holders to help naturally ventilate these stairwells, leaving the unit heaters operational. All temperature transmitters and sensors on all four air handling units were calibrated. The pilot positioners were adjusted and offsets put in to keep from pulling in mechanical room air through the relief dampers during all modes of operation. There are ~100 VAV boxes in the building. Each box and thermostat was inspected for proper operation and calibrated. Several rooms were being over-ventilated so the CFM numbers were reduced per heat load calculations.

Lincoln Hall

The air handling units (AHUs) providing air conditioning were maintain-ing space conditions in offices and classrooms based on a guessed schedule prior to people re-occupying the spaces. The primary energy conservation method was scheduling the AHUs off during tighter non occupied hours. Single technology wall mounted occupancy sensors were removed from ~130 offices and dual technology low voltage sen-sors were installed to UIUC and ASHREA standards. To maintain comfort conditions, all thermostats were calibrated and the heating valves were inspected for proper operation. There are approximately 235 VAV’s in the building. Each VAV was inspected for proper operation and calibration. The airflows were also balanced allowing in many cases for a reduction in flow to the spaces, resulting in fan energy savings without compromising comfort.

Conclusion

  • Business Instructional Facility, 33% savings
  • David Kinley Hall, 42% savings
  • Gregory Hall, 22% savings
  • Krannert Art Museum, 
  • Freer Hall, 32% savings
  • Material Sciences and Engineering, 19% savings
  • Admissions and Records, 64% savings
  • Art and Design, -1% savings = 1% increase
  • Temple Hoyne Buell Hall, 5% savings
  • Lincoln Hall, 57% savings

Project Team

  • Project Leader:

    Karl Helmink

Themes

Project Location(s)

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