Computing Services Center

Continuous Commissioning Report for the Computing Services Center Building #516 Submitted to: Utilities Energy Office Physical Plant Department Texas A&M University Prepared by: Energy Systems Laboratory 3/31/2006

Executive Summary The building assessed in this report is the Computing Services Center. It is a two-story building consisting of offices, computer labs, and the main computer equipment for the University. It is located on the main campus of Texas A&M. The HVAC system includes one multi-zone unit, one single duct CAV unit, one single duct VAV unit, three fan coil units, and six Liebert units. A DDC control system operates the VAV unit, the fan coil units and the Liebert units. A pneumatic control system operates the multi-zone and single duct units. The Continuous Commissioning measures that were implemented was the calibration of thermostats throughout the original part of the building and a new static pressure schedule for AHU-1. This was performed in December 2005. Furthermore, six measures were proposed that have yet to be implemented which are a) replace the existing 10 HP motor on the single duct air handling unit with a 3 HP motor, b) repair or replace the chilled water valve on FCU-3, c) begin using heating water in the newer area of the building to assist with heating, d) move the thermostat or refrigerator in room 1002, e) clean and open the return air vents in room 112, and f) upgrade the building lighting from T12 to T8 lamps. It is hoped that these measures will be implemented to complete this phase of the Continuous Commissioning process for this building. The comfort issues identified previously in the building have been resolved by the measures implemented. The calibration of thermostats help maintain comfortable room temperatures and a flexible supply duct that had been disconnected has been repaired. It is estimated that implementation of the proposed Continuous Commissioning measures would result in an additional $5300 per year savings. It is recommended that these measures be implemented so that the maximum amount of savings can be achieved.

Acknowledgements The Continuous Commissioning (CC ) process detailed in this report was a collaborative effort among the Energy Office, Area Maintenance, and the Energy Systems Laboratory at Texas A&M University. Many persons from each entity are responsible for the work done in the building, from the field and comfort measurements and CC measures determination, to the maintenance and controls items implemented. This document is designed to serve as a deliverable from the Energy Systems Laboratory to the Energy Office, and primarily details the CC activities and measures in which the Energy Systems Laboratory has been involved. For information concerning the Office of Energy Management please contact Homer L. Bruner, Jr. at (979) 458-2800. The lead CC investigator for this building was Hui Chen. For additional information regarding the information in this report or the overall Continuous Commissioning program at the Energy Systems Laboratory, please contact Song Deng at (979) 862-1234. i

Table of Contents I. Introduction... 1 II. Facility Information... 1 A. General Building Description... 1 B. HVAC& Lighting System Description... 2 III. Continuous Commissioning Activities... 4 A. Existing Building Conditions (Pre-CC)... 4 1. Existing HVAC Conditions... 4 2. Existing Comfort/Indoor Air Quality Conditions... 5 B. Continuous Commissioning Measures... 6 1. Implemented Measures... 6 2. Proposed Measures... 7 IV. Requested Action... 8 V. Building Comfort Improvements... 8 VI. Savings Analysis... 9 VII. Retrofit Recommendations... 9 VIII. Conclusions... 9 Appendices... 10 ii

List of Figures and Tables Figure 1. Computing Services Center... 1 Figure 2. Computing Services Center location... 2 Table 1. Building pumping information.... 3 Table 2. HVAC system airflow design information.... 4 Table 3. Summary of implemented CC measures in building... 6 Table 4. Summary of proposed CC measures that have not been implemented... 7 iii

I. Introduction Since 1997, more than 70 TAMU - College Station buildings have been commissioned, resulting in energy savings to the University of millions of dollars. For the fiscal year 2006, 25 buildings (totaling 2.5 million square feet) have been identified to be commissioned, of which the Computing Services Center is the eleventh. This building was identified as a prime candidate due to the extended amount of time since it was last commissioned. Commissioning began October 2005 and was completed in March 2006. II. Facility Information A. General Building Description Figure 1. Computing Services Center. 1

Figure 2. Computing Services Center location. The Computing Services Center, pictured above in Figure 1, was constructed in 1959 with an addition in 1993 and is located on the Texas A&M main campus (see Figure 2 above). It is home to the main computer equipment for the Texas A&M campus and consists primarily of offices, computer laboratories, and a large server room. The building has two floors for a total area of 30,464 square feet (22,848 ft 2 original and 7,616 ft 2 addition). It is generally occupied weekdays 8:00 a.m. to 5:00 p.m. The building was previously commissioned in 1999. B. HVAC& Lighting System Description The chilled water system in the building utilizes two 20 hp, 438 gpm pumps with VFD run by EMCS control in the new section and one 7.5 hp constant speed, pneumatic pump in the original section. The pumps in the new section and the control valve are DDC controlled by pressure differential. The piping system for the new section is two-way variable speed flow without bypass. The piping system in the old section is three-way constant speed flow with bypass. The heating water system utilizes two 1 hp, 40 gpm constant speed pumps with DDC control in the new section. The old section does not have a pump and operates with hot water directly from the loop (which can flow either way since no check valve is present). The control valve is DDC controlled by pressure differential. The piping system is two-way constant speed flow without bypass. A summary of the building pumping information is shown below in Table 1. 2

Table 1. Building pumping information. CHW System HW System Number of pumps 3 2 Pump control source APOGEE (2)/ Pneumatic (1) APOGEE Pump speed control VFD(2)/Constant(1) Constant Pump speed control method Bldg Valve control method Piping system type DP DP Two-way variable speed without bypass (2)/Twoway constant speed DP Two-way constant speed without bypass Control valve type DDC DDC Nameplate GPM 438 (2) 40 Nameplate Head (ft) 85 (2) 30 Nameplate HP 20 (2) 1 Nameplate RPM 1750 (2) 1730 The building also has an air cooled, reciprocating chiller, ACC-1, which is used as backup for the building if plant water supply is insufficient. Two constant air volume AHUs, both in the basement mechanical room, serve the original section of the building. AHU 1 is a single-zone air handler unit which serves room 112 exclusively. AHU 2 is a multi-zone unit with seven zones and serves this entire section of the building. Room thermostats control the mixing damper position for each zone. In the new section, one single-zone variable air volume (VAV) air handling unit (AH-1) serves a classroom, printing room and hallway. Three fan coil units (FCUs 1-3) supply conditioned air to the pump room, battery room, and transformer room, respectively, on the first floor. Each fan coil unit has a thermostat which controls its chilled water and hot water valves. A Liebert unit (CRU-1) serves room 110, a computer equipment room. Five other Liebert units (CRUs 2-6) serve the second floor. 3

Table 2. HVAC system airflow design information. Building Name: Computing Services Center Total Area: 30,464 ft 2 Unit Function Service Supply cfm Fan HP AHU 1(Multi-Zone) Supply Old Section 20380 10 AHU 2 (SD VAV) Supply Room 112 (Old Server Room) 13000 10 AH-1 Supply New Section classroom, printing room, and hallway 6318 5 FCU-1 Supply Pump Room 1600 ¾ FCU-2 Supply Battery Room 1300 ¾ FCU-3 Supply Switch Gear Room 3000 1.5 CRU-1 Supply Room 110, computer equipment room 9100 5 CRU-2 Supply Server Room 9300 5 CRU-3 Supply Server Room 9300 5 CRU-4 Supply Server Room 9300 5 CRU-5 Supply Server Room 9300 5 CRU-6 Supply Server Room 9300 5 EF-1 Exhaust Battery Room 600 1/6 EF-2 Exhaust 2 nd Floor Computer Room Smoke Removal 8000 1.5 EF-3 Exhaust Crawl Space Ventilation 3000 1.5 The lighting system in the building is composed of T12 lamps on all floors. III. Continuous Commissioning Activities A. Existing Building Conditions (Pre-CC) 1. Existing HVAC Conditions At the time commissioning began, it was discovered that the two hot water pumps serving the new section of the building were off and had not operated in approximately two years. Since no cold complaints had been received during that time, it has been decided that this scenario would continue. While this measure certainly saved energy by eliminating heating in the building, it also allowed chilled water and cooling airflow problems to be more easily identified. The space temperature for FCU-3, which serves a switchgear room, was recorded at 61.3º 4

F. It was discovered that the chilled water valve was not functioning. It was not able to close at all. It was unclear whether this was the result of a bad valve or if the valve had intentionally been dismantled to maintain full cooling to the switchgear room at all times. Either way, a significant amount of over-cooling was occurring in the room. One of the concerns of building mechanics is related to the buildup of hydrogen and harmful vapors in the battery room near the switchgear room. The exhaust fan serving this area (EF-1) was not functioning at the time of commissioning and the battery room door was kept open in an attempt to better circulate the air. This may have been a contributing factor to the desire to keep FCU-3 in full cooling to provide the maximum amount of airflow circulation, if in fact the full cooling was intentional. The exhaust fan for the battery room was repaired during the time commissioning took place, however. For the new section, space temperatures being controlled by VAV boxes served by AH-1 were all found to be significantly below their set point. The set points on several were also found to be lower than the campus initiative of 76º F. Additionally, a flexible duct just upstream from one of the terminal boxes had come loose, dumping all of the supply air into the return plenum which created low return air temperatures and eliminated the supply flow to the space. Also, in room 1002, the thermostat was found to be located directly behind a refrigerator, creating a false room temperature reading that would constantly call for cooling. Room 112 in the old section originally housed a mainframe computer and has since been converted to office space. It was discovered that the single duct AHU which serves exclusively this room (AHU 1) is a constant volume unit supplying 13,000 cfm of air. Additionally, the room has supply diffusers branching from the multi-zone AHU. The supply air to this room with its different-than-design usage was found to be very excessive. Room 112 has four return grills, each divided into two sections. The louvers on one section of each return grill were found to have been closed and the other section of each was thoroughly clogged. This caused a low level of return air from the room to the air handling unit, making the room very positive. It was discovered that AHU 1 (serving 112) had a torn canvas between the return air section and the coil section and that the heating water control valve was not functioning. The multi-zone unit in the old section was found to have a bad chilled water control valve. 2. Existing Comfort/Indoor Air Quality Conditions At the time commissioning began, the overall building indoor air quality was found to be good. Several areas in the building received excess supply airflow, yet despite the lack of heating ability in the new section, cold complaints were not received. As mentioned, one area received hot complaints due to the supply air being dumped directly to return from a 5

disconnected flexible duct. This was the only comfort complaint discovered at the time of commissioning. B. Continuous Commissioning Measures 1. Implemented Measures Table 3. Summary of implemented CC measures in building. Category CC Measure Result Thermostats Static pressure schedule Calibrated room thermostats. Reset Static pressure for AHU-1 Improved temperature control and comfort. Cooling flow optimization based on space load To resolve the problems described in the previous section, two Continuous Commissioning measures were implemented in the building and are shown in Table 5. The pneumatic thermostats in the old section of the building were calibrated. Two of these thermostats, rooms 1113 and 1115, do not function properly and should be replaced. A new static pressure schedule for AHU-1 was implemented to base the cooling on the space load. The control program monitors the static pressure in the duct and modulates the vanes to maintain a specified pressure at the VAV boxes. 6

2. Proposed Measures Table 4. Summary of proposed CC measures that have not been implemented in the building and their estimated potential savings. Category CC Measure Purpose Estimated Potential Savings AHUs AHUs Heating Water Thermostats Return Air Lighting Replace 10 hp motor and sheaves on single duct AHU serving room 112 with 3 hp motor Repair or replace chilled water valve on FCU-3 Begin using heating water in the newer area of the building to assist with heating Move T-stat or refrigerator in room 1002 Clean and open the 4 return air grills for room 112 Upgrade T12 lamps to T8s Reduce excess flow, energy savings from electricity and chilled water consumption Eliminate excess cooling, chilled water usage Improve comfort Improve comfort, reduce cooling needed Increase comfort, reduce excess cooling of outside air Electricity savings $3000 $750 N/A N/A $200 $1,350/year Six Continuous Commissioning measures are proposed that have not been implemented. Table 6 above lists these measures with a rough estimate of how much each measure would save if implemented. Their implementation will complete this phase of Continuous Commissioning for this building and will correct the remaining problems with building performance. The first of the proposed measures is to replace the 10 hp fan motor on the single duct AHU in the old section serving room 112 with a 3 hp motor and replace the sheaves. As mentioned, this constant air volume unit supplies 13,000 cfm of air to the room presently. It is estimated that only 4,000 cfm of supply air is needed for this room with its current usage. A 3 hp motor will provide the power needed to supply this amount and will reduce the electricity, chilled water, and hot water usage considerably. The second of the proposed measures is to repair or replace the chilled water valve on FCU-3. As mentioned, the space temperature near this unit was 61.3º F, which indicates 7

significant amounts of over-cooling. Since the exhaust fan in the battery room has been repaired, FCU-3 is not needed for air circulation through that room. The battery room door can be closed. The combination of FCU-2 and the exhaust fan can take care of the air circulation needed. In this way, a substantial amount of chilled water can be saved. The third proposed measure is to begin using heating water in the newer area of the building to assist with heating which will improve building comfort. The fourth proposed measure is to move the thermostat or refrigerator in room 1002. The thermostat is located directly behind a refrigerator, creating a false room temperature reading that would constantly call for cooling. This measure will improve comfort and reduce needed cooling. The fifth proposed measure is to clean and open the return air grills for room 112. As stated, each grill has two sections. One section is closed off and the other is clogged with debris on each grill. All four should be cleaned and opened to allow the proper amount of return to return air from room 112 to reach the air handling unit. This will decrease the overall amount of cooling required for outside air as more return air will be used by the air handling unit. The sixth proposed measure is a lighting retrofit in the building. It is recommended that the T12 lamps currently in the building be upgraded to T8 lamps in order to reduce the electricity consumption of the building. IV. Requested Action As mentioned earlier, it is requested that the thermostats in rooms 1113 and 1115 of the old section of the building be replaced, as they no longer function properly. It is also requested that the bad heating water valve and torn canvas on the single duct CAV unit in the old section be repaired or replaced and that the bad chilled water valve on the multizone unit be repaired or replaced. V. Building Comfort Improvements As discussed previously, one of the primary objectives of Continuous Commissioning is to improve occupant comfort levels in buildings. As noted, few comfort issues existed in the building before commissioning with the exception of hot complaints stemming from a disconnected supply duct. This issue was repaired and the pneumatic thermostats in the building were calibrated or recommended to be replaced. 8

VI. Savings Analysis At this point in the commissioning process, post-cc data is unavailable and thus savings cannot be determined. These values will be given at a later date by the ESL data analysis group. It is estimated that implementation of the proposed Continuous Commissioning measures would result in a $5,300 per year savings. VII. Retrofit Recommendations No retrofits are recommended for the building at this time. VIII. Conclusions The Computing Services Building has been a part of the A&M system since 1959. The fact that it had been several years since its last commissioning made it a good candidate for Continuous Commissioning. The process was performed over a period of five months. It is believed that the measures that have been implemented up to this time will save on energy costs, in addition to improving comfort in the building. If the proposed measures are implemented, it is estimated that an additional $5,300 per year can be saved and the remaining comfort issues can be resolved. Better energy efficiency will occur in the building, as well as, an increase in the productivity of occupants who will be more comfortable in their working environment. It is recommended that the proposed issues be resolved and the proposed measures be implemented to maximize the value of the Continuous Commissioning of this building, and most importantly, to maximize energy savings and comfort levels in the building. In this way, the Texas A&M University campus can move forward in its quest for energy efficiency and the Continuous Commissioning process will have been beneficial in aiding in this endeavor. 9

Appendices 10

Appendix A: Summary of deferred maintenance issues in building at time of CC. Issue Status Replace thermostats in rooms 1113 and 1115. Repair or replace HW valve on SD CAV unit in old section. Repair torn canvas on SD CAV unit in old section. Repair or replace CHW valve on multi-zone unit in old section. Re-attach disconnected air duct to VAV box Pending Pending Pending Pending Completed 11