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FY09 RCx (Completed)
During the second year of Retrocommissioning (RCx), a second team was added in January 2009. The motto was now "Saving the Planet Two Buildings at a Time." In this fiscal year, the RCx efforts completed seven buildings.
Animal Sciences Lab
The air handling units providing air conditioning were maintaining space conditions 24/7/365 for zones made up entirely by office space. The primary energy conservation method was scheduling the AHU equipment serving those offices to operate only when occupied. Many lab occupants were unaware as to how their fume hoods worked and the amount of energy that was being consumed. A major education campaign was launched to encourage the lab occupants to “Shut the Sash” on the fume hood when not personally using it. Meanwhile RCx determined that the exhaust was drawn to the roof by two large constant volume exhaust fans. To maintain proper flow through fans, two bypass dampers modulate to allow outside air from the roof into exhaust header. As building patrons adopted the new culture to shut the sash, bypassed air reached 70%, allowing one fan to be shut off.
Chem & Life Sciences Lab
The laboratories were designed for air circulation rates of approximately 30 air changes per hour to condition the labs every hour of the year. Offices grouped together were maintaining conditions all year. RCx was able to find an existing pneumatic line originally designed for a chilled reduction emergency, extending to every floor which afforded an opportunity to replace the controllers at all offices to allow them to shut off during unoccupied hours. RCx facilitated meetings to address the air circulation rate, involving campus safety, facility managers, code officials and similar experts. These discussions led to discussions with national universities as to their methods and approach. The result was a lowering of the occupied circulation rate from 30 to 10 ACH and during unoccupied from 30 to 6 ACH. Making the above changes required RCx to visit every lab space to re-balance the airflows. Each office also required its VAV controller configuration to be changed from a normally open device to a normally closed device. Faulty VAV controllers were replaced as required. The IAQ was improved and the air noise levels were reduced improving occupant comfort.
The 14 air handling units (AHUs) providing air conditioning were maintaining space conditions 24/7/365. The primary energy conservation method was scheduling 12 of the AHUs serving the areas to shut completely off for 6 or more hours each day. The remaining units were scheduled to reduce airflows during unoccupied hours. An exhaust fan serving the restroom areas were brought over to DDC control and scheduled to operate when building was occupied. Various outside air dampers were severely corroded. These were causing unnecessary freezestat trips and undesired unit shutdowns. Outdoor air delivery to classrooms and spaces was not compliant with the ASHRAE standard 62.1. Therefore, these were replaced in a larger project. Every AHU was visited and each of its sensors were calibrated and the sequences of operations were verified.
One of the largest issues in the building was the duct liner insulation falling apart inside the duct and collecting in dampers, coils, and diffusers downstream throughout the building. This insulation was cleaned out of the system for improved IAQ. Laboratory room pressurization controllers were found to be nonfunctional, allowing the laboratory to become positively pressurized at times. Many labs share ceiling space. Lack of control of pressurization contributed to drafty spaces, lifting of ceiling tiles, and other pressurization similar pressurization issues. RCx constructed a custom solution and replaced each lab’s controller in order to allow for proper air tracking and negative pressurization in the laboratories. RCx re-balanced the labs and adjacent spaces to fix the pressurization and lower the unoccupied room air changes, avoiding large energy costs. Finally, there were many other maintenance issues resolved such as leaking coils, clogged humidifier nozzles, and damaged damper systems that were all detrimental to the performance of the building.
Mechanical Engineering Lab
The savings at the Mechanical Engineering Laboratory were a result of a variety of improvements made to the building systems. Various occupancy schedules were implemented for the building HVAC systems to save energy during unoccupied hours. The air handling units in the building were operating with large amounts of outside air and the variable air volume boxes in the room were in need of calibration. Programming was modified to several AHUs to address these issues. Controls were added to multiple exhaust fans to allow these to be shut down during unoccupied hours. Outdated control systems on 3 AHUs that were no longer being serviced by maintenance personnel were upgraded to the latest systems available. Also, all sensors and safety devices were calibrated and checked on the AHUs to improve control, performance, and reliability. Web graphics were finally added allowing for remote energy tracking and troubleshooting.
Most of the air handling units (AHUs) providing air conditioning were maintaining space conditions 24/7/365. The primary energy conservation method was scheduling the AHUs serving the office areas to shut down for 8 hours a day and weekends. Web graphics were provided to the facility manager for HVAC system analysis from his desktop. Associated exhaust fans in the building were shut down during unoccupied hours. A Universal Network Controller (UNC) was installed to allow for web graphics and remote energy monitoring and troubleshooting. Various control upgrades were performed, improving the control sequences to avoid energy waste.
The air handling units (AHUs) providing air conditioning were maintaining space conditions 24/7/365. The primary energy conservation method was scheduling the AHUs serving the office areas to shut down for 10 to 12 hours a day and some on the weekends. This was possible due to the perimeter radiation throughout the building. Many occupants had thermal comfort complaints, many of which were the direct result of leaking reheat and/or radiation valves. The RCx team noted these complaints, identified numerous (approximately 100+) bad valves and replaced these valves. This saved a significant amount of steam and chilled water, due to the unnecessary cooling cost associated with the reheat coils. Therefore, air quantities were able to be reduced, again pushing our savings higher. To help control the heating issues further, VFD’s were added to the existing heating water pumps controlling the radiation system. This allowed flow to be reduced based on use rather than relying on only outdoor temperature.
- Animal Sciences Lab, 25% savings
- Chemical & Life Sciences Lab, 22% savings
- Loomis Lab, 20% savings
- Madigan Lab, 28% savings
- Mechanical Engineering Lab, 36% savings
- Music Building, 26% savings
- Wohlers Hall, 45% savings
- FY09 RCx Summary Animal Sciences Lab
- FY09 RCx Summary Chem & Life Sciences Lab
- FY09 RCx Summary Loomis Lab
- FY09 RCx Summary Madigan Lab
- FY09 RCx Summary Mechanical Engineering Lab
- FY09 RCx Summary Music Building
- FY09 RCx Summary Wohlers Hall
- F&S article about second RCx team
- PDF slides from RCx FY09 ISTC Seminar presentation