Reynolds Medical Science Building - Utilities & Energy Services

Continuous Commissioning® Report

for the

Reynolds Medical Science Building

Building 1504

Submitted to:

Utilities Energy Office Physical Plant Department

Texas A&M University

Prepared by:

Energy Systems Lab

December 22, 2005

Executive Summary

The building assessed in this report is the Reynolds Medical Science building. It is a 4-story building consisting of labs, classrooms, and offices located on the west campus of Texas A&M University. The HVAC system is a single duct VAV with terminal reheat, and incorporates 22 air handling units. A pneumatic Johnson control system operates the AHU equipment while the water systems are operated by DDC. The baseline energy consumption for the building before Continuous Commissioning was $4.15 /ft2. The Continuous Commissioning measures that were implemented were an optimization of the chilled and hot water pumping system, an air balance for the restrooms, and an air balance for the animal labs. These measures were implemented between April 2005 and January 2006. Furthermore, several measures were proposed that have not yet been implemented, including further air quality improvement of the restrooms, allowing proper outside airflow into the building, operating the pumping system according to design flow, and cleaning out the make-up air units. These measures need to be implemented to complete this phase of the Continuous Commissioning process for this building.

Based on the Continuous Commissioning measures that have already been implemented in the building, it is estimated that $32,000 per year will be saved on utility costs. These savings will be verified over the next several months by an independent data analysis. It is further estimated that implementation of the proposed Continuous Commissioning measures, which includes the DDC upgrade, will result in an additional $249,000 per year savings. It is recommended that these measures be implemented so that the maximum amount of savings can be achieved. The comfort issues identified previously in the building will be resolved by the proposed measures. It is estimated that total annual savings of $281,000 will be achieved.

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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 Chenggang Liu. 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.

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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 B. Continuous Commissioning® Measures ................................................................. 7

1. Implemented Measures ....................................................................................... 7 2. Proposed Measures ............................................................................................. 8

IV. Requested Action ..................................................................................................... 10 V. Retrofit Recommendations ...................................................................................... 10 VI. Building Comfort ..................................................................................................... 11 VII. Savings Analysis...................................................................................................... 11 VIII. Conclusions.............................................................................................................. 12 Appendices........................................................................................................................ 13

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List of Figures and Tables

Figure 1: Reynolds Medical Science Building .................................................................. 1 Figure 2: Energy consumption data for Reynolds Medical Science Building................... 5 Table 1. Building pumping information. ........................................................................... 2 Table 2. HVAC system design information....................................................................... 3 Table 3. Measured HVAC system airflow information..................................................... 7 Table 4: Building comfort measurements........................................................................ 11 Table 5. Savings achieved from individual measures and associated payback periods. . 12

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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 fiscal year 2006, 25 buildings (totaling 2.5 million square feet) have been identified to be commissioned, of which the Reynolds Medical Science Building is the second. This building was identified as a prime candidate due to its high energy cost per square foot and frequent comfort problems. Commissioning began in April 2005 and was completed in January 2006.

II. Facility Information

A. General Building Description

Figure 1: Reynolds Medical Science Building

The Reynolds Medical Science building, pictured above in Figure 1, was constructed in 1983 and is located on the West campus of Texas A&M University. It is home to the College of Medicine, and consists primarily of labs, but also contains two lecture halls (1st & 3rd floors) and administrative offices on the 1st floor. The building has 4 floors for a total conditioned area of 170,000 square feet. The building stands alone except for a covered (and unconditioned) walkway that joins it with the Medical Center Library. It is generally occupied from 7 am to 10 pm seven days a week.

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B. HVAC & Lighting System Description

The chilled water system utilizes two 25 hp, 680 gpm constant speed pumps and one 15 hp, 340 gpm constant speed pump, all run by EMCS (energy management control system) control. The control valves are DDC controlled by water temperature. The piping system is two-way constant speed flow loop with bypass and pump bypass.

The heating water system utilizes two 15 hp, 360 gpm constant speed pumps and one 10 hp, 180 gpm constant speed pump, all run by EMCS control. The control valves are DDC controlled by water temperature. The piping system is two-way constant speed flow loop with bypass and pump bypass. A summary of the building pumping information is shown below in Table 1.

Table 1. Building pumping information.

CW System HW System Number of pumps 3 3 Pump control source EMCS EMCS Pump speed control Constant Constant Pump speed control method

N/A N/A

Bldg Valve control method

Water Temp Water Temp

Piping system type Two-way constant speed flow loop with bypass and pump bypass

Two-way constant speed flow loop with bypass and pump bypass

Control valve type DDC Pneumatic Nameplate GPM 680 360 Nameplate Head (ft) 100 100 Nameplate HP 15 10 Nameplate RPM 1750 1750

The HVAC system in the building is a single duct variable air volume (VAV) system with 22 air handling units (AHUs). The control system for the AHUs is pneumatic and is powered by Johnson controls, and the control system for the water system is DDC and is powered by Siemens. The total design supply flow in the building is 193,370 cfm, of which 51,800 cfm is outside air. There are 37 make-up air fans, designed for a total of 31,710 cfm. The total design exhaust flow from the building is 80,980 cfm, and is achieved with 62 exhaust fans and 60 fume hoods. Table 2 below gives an overview of the units comprising the building HVAC system, with their design information.

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Table 2. HVAC system design information. Building Name: Reynolds Medical Total Area: 144,000 ft^2

Unit Function Service Supply cfm Outside Air cfm Exhaust cfm Note

1 Supply 1st fl.-S. Central, interior 9200 4060 0

2 Supply 1st&2nd-S.West 15970 0 0

2A Supply 9200 9200 0

3 Supply 2nd-S.Central, interior 4700 2810 0

4 Supply 1st&2nd-S.East 11940 2360 0

5 Supply 3rd&4th-S.West 17,680 3620 0

6 Supply 3rd&4th-S.Central, interior 13,220 7710 0

7 Supply 3rd&4th-S.East 10,930 2760 0

8 Supply 1st-N.West 7780 780 0

9 Supply 1st-N.Central, interior 7420 1050 0

10 Supply 1st-N.East 5200 520 0

11 Supply 2nd-N.West 7190 1010 0

12 Supply 2nd-N.Central, interior 9960 1000 0

13 Supply 2nd-N.East 4770 2470 0

14 Supply 3rd&4th-N.West 15350 3070 0

15 Supply 3rd&4th-N.Central, interior 16270 4380 0

16 Supply 3rd&4th-N.East 11490 2300 0

17 Supply #1 Lecture-rm. 207 4500 900 0

18 Supply #2 Lecture-rm.433 4,500 900 0

20 Supply #1 Lecture-rm. 207 4500 900 0

21 Supply Projector Rm.-209 800 0 0

22 Supply Projector Rm.-434 800 0 0 Exhaust Exhaust Total 0 0 80,980

The majority of the building’s air handling units are single duct variable air volume units. The flowrates of the supply air fans are varied through the use of 2-speed motors (slow/fast), along with the use of an automatic discharge damper for all of these units except AHU-1. AHU-1 is the only unit that has a VFD. All exterior zone units have terminal reheat. AHUs-2,4,8,10,11, & 13 but do not have preheat coils, while AHUs-5,7,14 & 16 do have preheat coils. The total design supply air/design outside air for all exterior zone units is total/outside air 63,780/15,530 cfm. The interior zone units AHUs-1,3,9, & 12 are cooling only and AHUs-6 & 15 (Fig. 5) have preheat capabilities in addition to cooling. The total design supply air/design outside air flow for all interior zone units is 60,770/21,020cfm The interior zone units were originally equipped with enthalpy controlled economizer cycles. Relief air fans and relief air dampers operate jointly with the interior zone units through a building static pressure controller to maintain 0.01”WG of positive pressure.

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For zone control in both exterior and interior zones, an induction type variable air volume box controller modulates the primary air valve actuator to maintain the desired volume of primary air. Upon a call for full cooling, the primary air damper is 100% open and the induced air damper is closed. The induced air damper will fully open when the primary air damper closes to its minimum position. If the space temperature continues to fall below its’ set point, the hot water reheat coil valve will begin to open in the exterior zones. AHU-2a (9200cfm) is a 1986 upgrade to the building and is a 100% OA unit serving the animal lab area on the 2nd floor. Two lecture halls (2nd & 4th Floors) have their own dedicated HVAC units. AHU-17 (4500cfm) & AHU-20 (4500cfm) serve Lecture Hall I (2nd floor), and AHU-18 (4500cfm) serves Lecture Hall II (4th floor). AHU-17 & 18 (Fig. 6) are constant speed single duct heating and cooling units with enthalpy economizers. AHU-20 is a supplemental cooling only unit for the same lecture hall, also constant speed and 100% re-circulated air. The two lecture hall projector rooms are served by small AHUs 21 & 22. The main pump room on the 1st floor contains three (3) chilled water pumps, 15hp/25hp/25hp (20%/40%/40% of full flow), and three (3) hot water pumps 10hp/15hp/15hp(20%/40%/40% of full flow). The constant speed pumps were designed for staged operation to meet full and part-load conditions. The original building prints show 60 fume hoods for a maximum building exhaust flowrate of approximately 80,000cfm. Make-up air for these hoods is brought into the building through 1 of 4 make-up air intakes in each of the 4 corners of every floor. This air is heated as required through hot water coils with 3-way valves and circulator pumps that are energized upon the valve opening. A small individual make-up air fan whose suction is tied into the makeup air intake duct provides make-up air to each hood. Currently the majority of the building uses T8 light bulbs. In the hallway, however, there are some mercury vapor spotlights. It is recommended that the mercury vapor spotlights be upgraded to compact fluorescent lights. It is also recommended that motion sensors be installed in the labs and restrooms.

III. Continuous Commissioning® Activities

A. Existing Building Conditions (Pre-CC)

Using the Energy Office database maintained by ESL, the following pre-CC energy consumption data was obtained. The chilled water consumed 0.186 MMBtu/yr-ft2, while the hot water consumed 0.032 MMBtu/yr-ft2. The data also showed 29.1 kWh/yr-ft2 of electricity consumed. This equates to $1.40/sq-ft for chilled water, $0.42/sq-ft for hot

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water, and $2.33/sq-ft for electricity for a combined pre-CC total cost of $4.15/sq-ft. A graphical representation of energy consumption data is shown in Figure 2.

Figure 2: Energy consumption data for Reynolds Medical Science Building.

Prior to the start of any commissioning activities a building walkthrough is conducted to get a sense of the overall building operations and performance. Without any measurements, several items distinctly suggested that the building was operating out of control. In viewing the pump room it was discovered that only one of the three building chilled water pumps was in operation. The other two pumps were partially disassembled and appeared to be under repair. Since the one operable pump was only designed to handle 40% of the building load, the cooling load on the building had to be reduced to keep temperatures within acceptable conditions. Further investigation showed that this was accomplished by either closing the outside air (OA) dampers to most AHUs or completely blocking the OA ductwork with plywood. The latter was found to be the case on more than 2/3 of all the units that had no OA. In a later visit to the building in March 2005, the commissioning team discovered that one 40% chilled water pump that had previously been disassembled, was now replaced by a new “used” pump that had been relocated from the neighboring Wehner Building. Upon further investigation it was determined that the pump was installed backwards, and another pump with the proper flow orientation would be required. The commissioning team shared this information with those responsible for the installation, and a new pump has since been ordered. It was also noted that none of the hot water pumps were running. Through questioning Area Maintenance and monitoring hot water (HW) energy consumption, it was determined that the 20% HW pump failed on 1/18/2005. Area Maintenance has explained that the 40% HW pumps provide far greater flow and pressure than is required

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by the building. So without the 20% pump available, they feel that operating on plant pressure alone is a better solution than turning on a larger pump. At the time of this report, the 20% pump has not been repaired. Additional problems were found by opening the AHU control panels in the mechanical rooms. Most control panels had several missing components, controllers that were bypassed or dialed out to full cooling, and/or water in the control air lines. On the main interior and exterior AHUs (AHUs 1 – 16), nearly all of the chilled water valves were wide open and not controlling. In fact, about 70% of all the control valves had some sort of mechanical problem and were not functioning properly. The static pressure control was also no longer controlling on these AHUs. The 2-speed fan motors were set manually to high, and most of the discharge dampers were no longer operable. The interior zone economizer cycles were not functional. The controls for the Lecture Hall AHUs (17, 18, & 20) had been removed/disconnected and new room thermostats were now controlling chilled and hot water valves for units 17 & 18. The OA dampers are closed and the economizer cycles have been disabled. AHU-20, which serves the 2nd floor lecture hall along with AHU-17, shares the same room thermostat as AHU-17 for control of its chilled water valve. Further assessment of the facility was conducted by measuring the discharge air temperature of the AHUs. Appendix E highlights the effect of having just one building chilled water pump in operation. Despite the call for full cooling from most of these units, it is a struggle for some of them to achieve discharge temperatures below 58-61ºF, which will lead to a struggle with building humidity control. The make-up air systems for the fume hoods were also inspected. Both the filters and hot water coils were solidly plugged with debris. Insufficient outside air due to the conditions of both the fume hood make-up system along with the closed off make-up to the AHUs has created significantly negative building pressures. The effects of this are as follows:

1) Energy waste resulting from the exhausting of conditioned air. 2) Infiltration of unconditioned outside air can lead to human discomfort with

drafts in the winter and humidity control problems in the summer. The measured HVAC system airflow information is summarized below in Table 3.

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Table 3. Measured HVAC system airflow information. Building Name: Reynolds Medical Total Area: 144,000 ft^2

Unit Function Service Supply cfm Outside Air cfm Exhaust cfm Note

1 Supply 1st fl.-S. Central, interior 4,280 0 0

2 Supply 1st&2nd-S.West 14,900 980 0

2A Supply 9,350 9,350 0

3 Supply 2nd-S.Central, interior 4,820 0 0

4 Supply 1st&2nd-S.East 10,050 2,270 0

5 Supply 3rd&4th-S.West 12,850 600 0

6 Supply 3rd&4th-S.Central, interior 5,555 800 0

7 Supply 3rd&4th-S.East 10,200 400 0

8 Supply 1st-N.West 2,320 0 0

9 Supply 1st-N.Central, interior 4,030 0 0

10 Supply 1st-N.East 3,110 0 0

11 Supply 2nd-N.West 1,210 1,660 0

12 Supply 2nd-N.Central, interior 6,900 0 0

13 Supply 2nd-N.East 3,360 0 0

14 Supply 3rd&4th-N.West 10,540 200 0

15 Supply 3rd&4th-N.Central, interior 14,125 400 0

16 Supply 3rd&4th-N.East 10,358 0 0

17 Supply #1 Lecture-rm. 207 6,300 400 0

18 Supply #2 Lecture-rm.433 5,500 0 0

20 Supply #1 Lecture-rm. 207 5,800 0 0

21 Supply Projector Rm.-209 -- n/a 0

22 Supply Projector Rm.-434 -- n/a 0 Exhaust Exhaust Total 0 0 37,673

B. Continuous Commissioning® Measures

1. Implemented Measures To resolve the problems described in the previous section, a number of Continuous Commissioning measures have been implemented in this building. The first measure implemented was to optimize the chilled and hot water pumping system control schedule. This was done to better control the operation of the pumps, thereby reducing energy consumption. The result of this measure was savings in chilled and hot water consumption.

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The second measure implemented was an air balance for the restroom exhaust throughout the building. This was done after noticing that there were high temperatures in some of the restrooms. The air balance mitigated some of the problems. In order to solve this problem completely, however, supply air diffusers need to be installed for each restroom. See the proposed measures section below, along with Appendix B for details. The third measure implemented was an air balance performed on the animal labs on the 4th floor. An air balance was performed during a previous troubleshooting assignment (June 2002) and nonfunctioning reheat valves were replaced in order to maintain a constant design temperature in the lab. Not only did this CC measure result in a constant lab temperature, but bad odors that had previously been a problem were removed because the air balance exhausted the proper amount of air from the labs as designed. The air balance performed during 2002 was verified during the current CC process. See the table in Appendix A for a summary of the Continuous Commissioning measures that have been implemented in this building.

2. Proposed Measures Several Continuous Commissioning measures are proposed that for various reasons have not yet been 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 a part of a CC measure mentioned above that has only been partially completed. As stated before, action was taken to improve the comfort of the restrooms throughout the building. So far, only an air balance has been performed. Supply air diffusers still need to be installed in the restrooms and the exhaust ducts in the restrooms still need to be cleaned. These actions will further improve comfort by reducing temperatures and odors in the restrooms. The second proposed measure is to allow the proper amount of outside air to come into the building. By performing this CC measure, indoor air quality will be significantly improved. This measure will result in lower humidity levels, will help labs ensure a supply of fresh air, will reduce undesired infiltration, and will help lower CO2 levels. This measure has not been implemented because many of the outside air dampers do not function properly and/or the outside air duct has been boarded up. See requested action below for details. The third proposed measure is to operate the chilled and hot water pumping systems according to design flow. This measure’s purpose is to increase the cooling and heating capacity of the building to more adequately meet the building demands function. This measure will also help reduce the humidity levels in the building. Because only one of the three chilled water pumps is currently running in the building, it is often a struggle to achieve AHU discharge air temperatures below 58°F, resulting in higher than desired space temperatures and humidity levels.

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The fourth proposed measure is to clean out the make-up air system. The reason for this measure is because the filters and coils in the make-up units are blocked, preventing adequate flow. This results in energy waste from exhausting conditioned air instead of make-up air, and occupant discomfort from cold drafts of air next to building exits in the winter and increased humidity in the summer. By implementing this measure, these problems should be reduced. The fifth proposed measure is a control system retrofit to Direct Digital Controls (DDC). The existing pneumatic controls have deteriorated to the point of requiring a complete replacement. Substantial energy savings are obtainable through the reimplementation of such measures as the reset of discharge air temperature, the economizer cycles, and supply fan speed control. DDC will provide a more precision and maintainable control system that can be more easily monitored to ensure the persistence of energy savings. The total amount of AHUs to DDC upgrade is 22. They are AHUs 1-22 and 2A (AHU 19 was removed from the original design). There are several other items related to the potential DDC upgrade. AHU 8 had a two-speed motor that was replaced with a single-speed motor. Installing a VFD on this fan will provide fan power savings and provide a variable static for its VAV system. Another measure to be implemented during the DDC retrofit is to replace all nonfunctional control valves. Approximately 70% of the control valves on AHUs are not functional. The failure of the majority of chilled water control valves will begin to cause excessive cooling and energy waste when a second chilled water pump is put online. Currently, there are many problems with parts of the existing pneumatic control system that are nonfunctional such as control panels with missing components, controllers that are bypassed or dialed out to full cooling, and/or water in the control air lines. These sorts of problems will not be necessary to fix with the DDC upgrade because they will no longer be needed. AHUs 2 through 16 (except 8) have two-speed motors for their supply air fans, but the motors run at high speed all the time due to failed pneumatic controls. This problem will be solved through programming after a DDC upgrade. However converting two-speed controls to VFD controls will achieve additional energy savings. When VFDs are installed, two-speed starters for those fans will need to be eliminated and the two-speed motors will need to be permanently wired for high speed operation. Then, supply air dampers for those two-speed fans/motors need to be taken out. The relief fans of AHU 1, 3, 6, 9, 12, and 15 need VFDs for economizer operation. See the table in Appendix B for a summary of the Continuous Commissioning measures that still need to be implemented in this building.

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IV. Requested Action In order to maximize the performance of the building and its potential energy savings, it is requested that a number of maintenance and controls issues be addressed in the building. These include issues that need resolving in order to implement the proposed Continuous Commissioning measures, as well as, general deferred maintenance issues. To be able to implement the proposed measure to improve the restroom comfort level, supply air diffusers need to be installed in the restrooms and the restroom exhaust ducts need to be cleaned. Supply air diffusers of 50 cfm need to be installed in the restrooms on the 1st, 2nd, and 3rd floors while supply air diffusers of 100 cfm need to be installed in the restrooms on the 4th floor. In order to allow the proper amount of outside air to come into the building, outside air dampers and actuators need to be repaired/replaced and the outside air ducts need to have all boards removed from them. In order to implement the proposed measure to run the pumping system at design level, two chilled water pumps need to be replaced and two hot water pumps need to be replaced. In order to optimize the active components of the chilled water control system, chilled water valve controllers need to be replaced. For a summary of the requested actions needed for Continuous Commissioning measure implementation, see the table in Appendix C. Other maintenance issues that were noticed in the building that need attention include replacing AHU filters, cleaning and back flushing coils, and tightening fan belts. For a summary of these deferred maintenance issues, see the table in Appendix D.

V. Retrofit Recommendations In assessing the building, it has been determined that a retrofit of the pneumatic control system to DDC for the AHUs would be beneficial to the building performance and energy consumption. It is estimated that this retrofit would cost approximately $120,000, and would have a simple payback of 0.4 years, making it a feasible investment. As part of the retrofit to DDC, an installation of a VFD on AHU 8 is necessary. For this item, the estimated cost is $4,000, with a simple payback time of 0.8 years. After the control system has been retrofitted to DDC as explained above, it is recommended that a VFD be installed on AHUs 2-7, 9-16 and on the relief fans for AHUs 1, 3, 6, 9, 12, and 15. The total cost for this additional retrofit is $80,000, with a simple payback of 1.9 years. Once these retrofits have been implemented, it is recommended that follow up commissioning be performed by ESL in order to set up AHU duty cycles, economizer cycles, and temperature reset schedules for additional energy savings.

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VI. Building Comfort During the commissioning process, comfort level measurements were taken throughout the building. A table summarizing the findings is given below.

Table 4: Building comfort measurements

Floor No. Location

Temperature (F)

Relative Humidity (%)

CO2 (ppm)

Outside 83.9 55.5 370 1 Hallway by 104 73.0 62.0 508 1 Room 117 67.9 66.7 464 1 Room 153 72.7 61.4 501 1 Hallway by 157 72.1 62.8 562 2 Lecture Hall 68.8 74.2 799 2 Room 216 73.6 64.4 870 2 Room 243 73.5 59.4 558 3 Room 314 75.2 62.5 513 3 Hallway by 308 70.0 65.1 602 3 Hallway by 364 71.5 63.9 582 3 Room 353 73.4 60.3 499 4 Room 414 74.4 58.5 550 4 Hallway by 408 74.9 59.9 535 4 Room 455 71.1 58.8 605 4 Lecture Hall 66.9 69.9 618

In addition to the data in Table 4, the building pressure (measured in the hallway) was taken relative to outside and was found to be -0.04 in. W.G. The pressure inside the labs should be much higher than this level due to the exhaust fans. The reason for such a high negative pressure is the boarded outside air ducts for many of the AHUs. After reviewing the data in Table 4, absolute humidity levels of the building were compared with the outside air. The absolute humidity outside was approximately .014 while the absolute humidity of the lecture hall on the 2nd floor was .012. These values indicate that there is a significant amount of outside air entering the building through infiltration. While this air entering through infiltration makes CO2 levels acceptable, humidity levels in the building are higher than they should be because the infiltrated air is not being conditioned by any of the air handlers.

VII. 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.

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The estimated savings that can be achieved from each measure proposed are summarized in Table 5 below. A simple payback period has been calculated for each measure and for the entire project.

Table 5. Savings achieved from individual measures and associated payback periods.

Category Proposed Measure

EstimatedCost

EstimatedEnergy Savings

Estimated Cost

Savings

Estimated % Savings

Estimated Payback Period

Controls DDC Upgrade

and system optimization

$120,000 $281,000/yr 35% 0.4 years

Mechanical VFD

Installation (AHU 8)

$4,000 $5,000/yr 1% 0.8 years

Mechanical

VFD Installation for major AHUs

and relief fans

$80,000 $43,000/yr 6% 1.9 years

Mechanical Remove boards

from OA intakes

$0 -$80,000 -12%

Total $204,000 $249,000 30%

VIII. Conclusions

The Reynolds Medical Science Building has been a part of the A&M system since1983. High energy consumption and comfort problems in the building made it a good candidate for Continuous Commissioning. The process was performed over a period of nine months. It is estimated that the measures that have been implemented up to this time will save $32,000 per year on energy costs, in addition to improving comfort in the building. If the proposed measures and a major retrofit of the control system to DDC and VFD installation are implemented, an additional $329,000 per year can be saved, and the remaining comfort issues can be resolved. Removing boards from outside air intakes of AHUs will solve humidity problems in the building. This action, however, will increase the utility cost by $80,000. This would result in a total savings of $281,000 per year for this building, in addition to the increased productivity of occupants who would be more comfortable in their working environment. A number of issues have been identified that need to be addressed in order for the proposed Continuous Commissioning measures to be implemented. An additional list of deferred maintenance issues that need to be resolved has been generated. 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.

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Appendices

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Appendix A: Summary of implemented CC measures.

Category CC Measure Result

Controls Optimize the chilled and hot water pumping system. Reduced CHW & HW usage.

CC Air balance for restroom exhaust. Improved exhaust air flow distribution.

CC Air balance for 4th floor animal labs. Achieved comfort and met indoor air quality requirements of labs.

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Appendix B: Summary of proposed CC measures.

Category CC Measure Purpose

CC Improve air quality of restrooms throughout building. Improve comfort.

CC Allow proper outside air flow into the building.

Lower humidity, increase fresh air supply for labs, reduce infiltration,

and lower CO2 levels.

CC Operate pumping system according to design flow.

Lower humidity and provide more adequate cooling and heating.

Mechanical Clean debris from all make-up air units to allow proper flow.

Energy savings and comfort improvement.

Controls DDC upgrade on all AHUs. Energy savings and better control.

Mechanical After DDC upgrade, install VFD on AHU 8

Provide fan power savings and a variable static for VAV system.

Mechanical Replace all nonfunctional control valves.

Energy savings and better comfort control.

Mechanical

After DDC upgrade, convert two-speed motors to VFD for AHUs 2 thru 7 & 9 thru 16 & on the relief

fans for AHUs 1, 3, 6, 9, 12, & 15.

More efficient operation.

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Appendix C: Summary of requested actions needed before implementing proposed CC measures.

Requested Action Related CC Measure Status Install air diffuser with 50 cfm for

restrooms on floors 1, 2, & 3, and with 100 cfm for restrooms on floor 4. Also clean the restroom exhaust ductwork.

Improve air quality of restrooms throughout

building. Pending.

Repair/replace outside air dampers and actuators and remove boards from

outside air ducts.

Allow proper outside air flow into the building. Pending.

Replace two chilled water pumps and two hot water pumps

Operate pumping system according to design flow. Pending.

Replace chilled water valve controllers and control panel components.

Optimize existing control system. Pending.

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Appendix D: Summary of deferred maintenance issues in building at time of CC.

Issue Status

Replace AHU filters Pending.

Clean and back flush coils Pending.

Tighten fan belts Pending.

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Appendix E: Diagrams & Measurements

H

CC

C Supply FanOutside

Air 2-Speed

RA fromSpace

EXTERIOR ZONE UNITS with Preheat

Filters

CR

InducedReturn Air

SA toSpace

SP

T

1 3 4 56

2

Diagram 1: AHUs 5, 7, 14, 16

AHU 5 (4th floor South)

Location on Diag.

1

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 94.2 46.7 + 0.04 45 36” X 18” ID 201

2 77.1 56.3 - 0.05 658 38” X 28” ID 4860 One of two,

the other (52x22 ID) is inaccessible

3 75.5 58.5 - 0.56 X X X

4 75.7 58.8 -0.69 X X X

5 56.3 100 -1.07 X X X

24” = 5750 cfm 1831 fpm 6 58.3 94.3 + 3.80 2224

1 @ 24”⎠

1 @ 22”⎠ 12850

22” = 7100 cfm 2691 fpm

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Location on Diag.

1

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 97.9 33.2 + 0.06 13 30” X 18” ID 47

2 79.7 49.7 - 0.09 847 34” X 22” ID 4400

One of two the same size. The other is

inaccessible3 79.1 49.6 - 0.70 X X X

4 80.3 48.2 - 0.79 X X X

5 55.2 100 - 1.15 X X X

22” = 6050 cfm 2293 fpm 6 59.1 92.2 + 3.60 2117

1 @ 22”⎠

1 @ 20”⎠ 10200

20” = 4150 cfm 1903 fpm

AHU 14 (4th floor North)

Location on Diag.

1

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 89.8 61.5 + 0.08 45 30” X 18” ID 169

2 76.9 55.7 - 0.06 584 46” X 24” ID 4480



4 76.3 56.3 - 0.60 X X X

5 51.3 100 - 0.89 X X X

22” = 6500 cfm 2464 fpm 6 55.5 92.7 +5.75 1997 2 @ 22”⎠ 10540

22” = 4040 cfm 1531 fpm

20


Location on Diag.

1

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 84.4 80.5 + 0.06 27 30” X 24” ID 134

2 78.2 63.4 - 0.08 782 38” X 22” ID 4540



4 77.5 63.0 - 0.85 X X X

5 55.6 100 - 1.26 X X X

20” = 5844 cfm 2680 fpm 6 56.7 100 + 2.56 2375 2 @ 20”⎠ 10358

20” = 4514 cfm 2070 fpm

H

CC

C Supply Fan

Relief Fan

Relief Air

Outside Air 2-Speed

RA fromSpace

INTERIOR ZONE UNITSFilters

InducedReturn Air

SA toSpace

SP

T

1 4 56

2

3

Diagram 2: AHUs 6, 15

21


Location on Diag. 2

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 90.0 65.4 +0.05 38 72” X 36” ID 680

77.5 61.6 -0.01 327 46” X 18” ID 1880 2

75.5 66.0 -0.05 299 28” X 16” ID 930 2810 cfm 317 fpm

3 78.0 66.1 -0.19 X X X

4 78.0 63.5 -0.21 X X X

5 74.3 65.6 -0.27 X X X

18”= 1690 cfm =

956 fpm 18”=

705 cfm= 399 fpm

18”= 760 cfm= 430 fpm

6 68.0 77.8 +4.72 872 3 @ 18”⎠

1 @ 14”⎠ 5555

14”= 2400 cfm= 2245 fpm


Location on Diag. 2

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 83.5 82.0 + 0.04 35 72” X 36” ID 625

904 38” X 22” ID 5250 2 75.9 61.3 - 0.20

826 38” X 28” ID 6100 11350 cfm 860 fpm

3 74.0 62.2 - 0.96 X X X

4 75.0 64.6 - 0.96 X X X

5 55.9 100 - 1.55 X X X

20” = 5200 cfm 2385 fpm

18” = 4810 cfm 2723 fpm

18” = 2280 cfm 1291 fpm

6 58.3 93.5 + 4.56 1987

2 @ 18”⎠

1 @ 16”⎠

1 @ 20”⎠

14125

16” = 1835 cfm 1315 fpm

22

C

CC

R

InducedReturn Air

Supply FanOutside

Air 2-Speed

SA toSpace

RA fromSpace

EXTERIOR ZONE UNITS -Cooling Only

SP

T

Filters

1

2

3 45

Diagram 3: AHUs 2, 4, 8, 10, 11, 13

AHU 2 (2nd floor South)

Location on Diag.

3

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 85.7 56.4 - 0.16 1014 40” X 30” ID 8450

2 71.0 66.1 - 0.16 797 28” X 18” ID 2790

One of two, the other

(52x22 ID) is


4 58.9 93.9 - 0.89 X X X

5 59.3 94.9 + 3.21 2579

24”⎠

22” ⎠ 14901

23


Location on Diag.

3

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 93.6 44.7 -0.03 53 24” X 18” ID 106

2 73.3 59.3 -0.26 948 46” X 18” ID 5,450

One of two, the other

(38x18 ID) is

inaccessible 3 74.0 59.4 -0.41 X X X

4 54.7 97.7 -0.81 X X X

5 57.9 90.9 4.09 2,546

20”⎠

18” ⎠ 10,050

AHU 8 (1st floor North)

Location on Diag.

3

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 68.0 56.6 -0.03 53 24” X 12” ID 106

2 71.9 55.5 -0.03 239 42” X 28” ID 1,955

3 71.3 55.8 -0.06 X X X

4 52.1 99.0 -0.84 X X X

5 55.9 92.3 2.78 879 22”⎠ 2,320

24


Location on Diag.

3

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 72.1 57.6 -0.09 123 18” X 12” ID 185

2 72.8 58.0 -0.08 527 34“ X 22” ID 2740

3 72.4 57.7 -0.17 X X X

4 56.2 95.6 -2.97 X X X

5 58.1 91.5 +1.73 1426 22”⎠ 3110

AHU 11 (2nd floor North)

Location on Diag.

3

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 75.5 62.5 -0.02 44 24” X 18” ID 133

2 74.2 59.6 -0.02 160 38” X 28” ID 1185

3 73.5 61.3 -0.03 X X X

4 57.8 89.1 -4.07 X X X

5 63.6 75.1 +0.06 459 22”⎠ 1210


Location on Diag.

3

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 83.1 81.2 +0.03 5 36” X 24” ID 31

2 75.5 63.5 -0.12 570 34” X 22” ID 2960

3 75.9 64.2 -0.24 X X X

4 52.9 100 -0.54 X X X

5 56.6 93.9 +4.04 1901 18”⎠ 3360

25

C

C Supply Fan

Relief Fan

Relief Air

Outside Air 2-Speed

RA fromSpace

INTERIOR ZONE UNITS-Cooling OnlyFilters

InducedReturn Air

SA toSpace

SP

T

1

2

3 45

Diagram 4: AHUs 1, 3, 9, 12

AHU 1 (1st floor South)

Location on Diag.

4

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 90.3 68.6 -0.02 403 42” X 36” ID 4230

2 80.8 76.1 -0.01 11 34” X 22” ID 59

3 89.7 71.7 -0.12 X X X

4 60.1 97.2 -0.28 X X X

5 56.2 98.0 +1.10 1362 24”⎠ 4280


Location on Diag.

4

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 77.2 54.5 -0.14 143 48” X 24” ID 820

2 72.7 60.4 -0.13 1,151 28” X 18” ID 4,030

3 73.7 60.0 -0.50 X X X

4 58.3 92.9 -1.81 X X X

5 58.8 89.4 1.91 2,211 20”⎠ 4,820

26


Location on Diag.

4

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 72.6 56.0 -0.19 23 42” X 30” ID 197

2 72.8 56.4 -0.19 901 46” X 22” ID 3580

3 72.6 55.7 -0.31 X X X

4 56.7 95.1 -0.77 X X X

5 58.1 93.4 +3.20 1527 22”⎠ 4030


Location on Diag.

4

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 91.3 66.3 +0.02 7 54” X 30” ID 81

2 73.9 60.0 -0.27 766 52” X 28” ID 7750

3 74.0 59.2 -0.90 X X X

4 54.4 100 -1.17 X X X

5 57.0 98.0 +3.16 2196 24”⎠ 6900

C

CC

H Supply Fan

Return Fan

Relief Air

Outside Air

SA toSpace

RA fromSpace

LECTURE HALL UNITS

T

1

2

3

4 67

5

Filters

Diagram 5: 17, 18

27

AHU 17 (3rd floor center)

Location on Diag.

5

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 81.7 49.7 -0.34 70 22”X 22” ID 236

2 72.8 70.3 -0.66 X X X

3 73.5 68.5 -0.44 1874 22”X 22” ID 6300

4 73.3 68.5 -0.40 X X X

5 73.4 67.5 -0.67 X X X

6 61.7 100 -1.32 X X X

7 61.4 98.5 +0.62 1845 24” X 20” ID 6150


Location on Diag. 5

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 71.7 59.1 0.00 21 22” X 22” ID 70

2 65.9 71.3 -1.04 X X X

3 66.7 68.6 -0.58 1592 22” X 22” ID 5350

4 66.6 69.1 -0.55 X X X

5 66.7 69.0 -0.76 X X X

6 54.0 100 -1.34 X X X

7 55.8 100 +0.58 1650 24” X 20” ID 5500

28

C

CSupply Fan

SA toSpace

RA fromSpace

LECTURE HALL UNIT

T1

2 34

Filters

Diagram 6: 20


Location on Diag.

6

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 69.9 71.6 -0.8 2205 24” X 20” ID 7350

2 69.7 74.0 -1.06 X X X

3 64.3 91.2 -1.65 X X X

4 66.8 83.3 +0.32 1740 24” X 20” ID 5800

Projector Room Unit

SupplyFan 2RA

Filter

1To ProjectorRoom

C

C

Diagram 7: AHUs 21, 22

29

AHU 21 (2nd floor 209)

Location on Diag.

7

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 46” X 10” ID

2

AHU 22 (4th floor 434)

Location on Diag.

7

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 46” X 10” ID

2

Animal Lab Unit

H

CC

C Supply FanOutside

AirFilters

1 2 34 5

Filters HepaFilters

Diagram 8: AHU 2A

AHU 2A (2nd floor South)

Location on Diag.

8

Temperature

(°F)

RH

%

Pressure

In.H2O

Velocity

fpm

Duct Size

(L x W)

Flow

CFM Comments

1 85.3 61.3 -0.10 2,040 X 9,350

2 85.2 61.0 -0.15 X X X

3 58.8 96.4 -0.31 X X X

4 65.3 84.9 3.53 X X X

5 64.5 85.5 1.68 2,040 30” X 22” ID 9,350

Reynolds Medical Science Building - Utilities & Energy Services

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Transcript of Reynolds Medical Science Building - Utilities & Energy Services