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Summary Report
STATE ENERGY OFFICE
OF THE
NORTH CAROLINA DEPARTMENT
OF ADMINISTRATION
FOR
Demonstration Project
Utility Savings Initiative Demonstration Program
Prepared by Marina Ambrose State Energy Office North Carolina Department of Administration 1830-A Tillery Place Raleigh,NC 27604 1340 Mail Service Center
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TABLE of CONTENTS
TABLE OF CONTENTS ............................................................................................................................. 2 EXECUTIVE SUMMARY .......................................................................................................................... 3 ACKNOWLEDGMENTS ............................................................................................................................ 7 NC A&T STATE UNIVERSITY – GREENSBORO, NC ......................................................................... 8
1. NC A&T STATE UNIVERSITY ECM – REPLACEMENT OF EXISTING VALVES WITH THERMOSTATIC CONTROL VALVES ON STEAM RADIATORS......................................................... 9
2. NC A&T STATE UNIVERSITY ECM – INSTALLATION OF LIGHTING CONTROLS AND HIGH EFFICIENCY LIGHTING IN MCNAIR HALL ....................................................................................10
3. NC A&T STATE UNIVERSITY ECM – INSTALLATION OF VARIABLE AIR VOLUME CONTROL VALVE ON LABORATORY FUME HOOD IN CARVER HALL ............................................................11
4. NC A&T STATE UNIVERSITY ECM – DEMONSTRATION AND VERIFICATION OF ENERGY SAVINGS AVAILABLE THROUGH HVAC UPGRADE IN A UNIVERSITY BUILDING .........................12
APPALACHIAN STATE UNIVERSITY – BOONE, NC........................................................................13 1. APPALACHIAN STATE UNIVERSITY ECM – LIGHTING RETROFIT IN HEALTH PROMOTIONS
AREA OF VARSITY GYM .................................................................................................................14 2. APPALACHIAN STATE UNIVERSITY ECM – INSTALL T8 LAMPS AND OCCUPANCY SENSORS IN
KERR SCOTT HALL ROOMS 167 AND 207 ......................................................................................15 3. APPALACHIAN STATE UNIVERSITY ECM – INSTALL VARIABLE FREQUENCY DRIVES FOR CAP
BUILDING HVAC SYSTEM .............................................................................................................16 NC STATE UNIVERSITY – RALEIGH, NC ...........................................................................................17
1. NCSU ECM - REPLACE INCANDESCENT LIGHTS IN HALLWAY WITH COMPACT FLUORESCENTS, CARMICHAEL GYMNASIUM ................................................................................18
2. NCSU ECM - INSTALL T8 LAMPS AND OCCUPANCY SENSORS IN CLASSROOM 1402, BROUGHTON HALL .........................................................................................................................19
3. NCSU ECM - INSTALL T8 LIGHTS WITH DIMMING CONTROL AND OCCUPANCY SENSORS IN ROOMS 2209 AND 2210, COLLEGE OF TEXTILES ..........................................................................20
4. NCSU ECM - REDUCE HALLWAY LIGHTING FROM 4 LAMPS TO 2 LAMPS, RESEARCH IV ON CENTENNIAL CAMPUS ....................................................................................................................22
5. NCSU ECM - INSTALL OCCUPANCY SENSORS IN CLASSROOMS 3216, 3218, AND 4217 IN BROUGHTON HALL .........................................................................................................................24
6. NCSU ECM - MOVE OCCUPANCY SENSOR TO PREVENT FALSE TRIGGERS, BROUGHTON ROOM 2211 .................................................................................................................................................25
7. NCSU ECM - INSTALL OCCUPANCY SENSOR IN CLASSROOM 220, DABNEY .............................26 8. NCSU ECM - REACTIVATE GLYCOL HEAT EXCHANGER SYSTEM, CARMICHAEL GYMNASIUM . .........................................................................................................................................................27 9. NCSU ECM - PROGRAM AHU FANS TO DEACTIVATE DURING INACTIVE PERIODS, OLDER
SECTIONS OF CARMICHAEL GYMNASIUM .....................................................................................28 UNC – CHARLOTTE, NC .........................................................................................................................30
1. UNC CHARLOTTE ECM – ATKINS LIBRARY DAYLIGHT HARVESTING.......................................31
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Executive Summary This report summarizes the energy conservation measures (ECMs) that were undertaken by our four partner Universities – NC A&T State University-Greensboro, NCSU-Raleigh, Appalachian State University-Boone, and UNC-Charlotte. Altogether, there were 17 separate ECMs. Some of the ECMs that were implemented used similar strategies but the different locations offered additional data for each unique location and environment and, thus, gave a broader perspective about the ECM. Other ECMs were unique and tailored specifically for a certain environment. Together, all of the ECMs represent an important collaboration between the State Energy Office and the partner Universities. The following group of Energy Conservation Measures demonstrates excellent results in energy savings and payback period and should be recommended for all State Facilities:
• Program AHUs to deactivate during periods of inactivity o 43% energy reduction representing $9,500 annual savings and immediate
payback for NCSU ECM 9 • Incorporate thermostatic controlled steam valves in steam radiators
Low cost to implement – exceptional payback o 3 million Btu daily heat energy savings or $10,386/yr savings with 17 day
payback for NC A&T ECM 1 • Replace incandescent lights with compact fluorescents
This could be the biggest gain statewide for a modest expenditure o 19,053 kWh/yr actual energy savings and $2,012/yr cost savings with 3
month payback for NCSU ECM 1 • Reduce hallway lighting from 4 to 2 lamps where appropriate
Lighting requirements must be observed and maintained at a safe and practical level.
o 7,488 kWh/yr energy savings with 9 month payback by delamping 4 tube T8 lamps down to 2 T8 lamps for NCSU ECM 4
• Incorporate high efficiency lamps, occupancy sensors, and dimming controls separately or in combinations where appropriate Sites must be carefully chosen and systems must be monitored and remonitored for effectiveness.
o 2.91 year payback and $2,174 annual savings for NC A&T ECM 2 - combination of high efficiency T8 lamps and occupancy sensors
o 17,056 kWh/yr annual energy savings or 57% reduction in lighting energy use with 4 year payback for NCSU ECM 5 – installation of occupancy sensors
• Move occupancy sensors to prevent false triggers o 346 kWh/yr energy savings with 3 year payback for NCSU ECM 6
• Install Variable Frequency Drives (VFDs) in HVAC system o $10,000 annual energy savings with 4 year payback for ASU ECM 3
• Reactivate glycol heat exchanger system o Monthly fuel energy savings of 48.7 MMBTU for NCSU ECM 8
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• Installation of lab hood ventilation control systems o $1,076.88 annual energy savings per hood with 5.8 year payback for NC
A&T ECM 3 o Redesign of system to use common headers could be a better solution
The following group of Energy Conservation Measures could significantly reduce energy consumption although the payback is slightly higher than the group of ECMs mentioned above so these are possibly good candidates for new construction rather than retrofit:
• Installation of T8 lamps and occupancy sensors o 72% lighting reduction with 8 year payback by replacing 4 T12 lamps
with 3 T8 lamps and installing occupancy sensors for NCSU ECM 3 • Installation of T8 lights with dimming controls and occupancy sensors
o 30% power demand reduction with 10 year payback for NCSU ECM 2 • Replace ceiling incandescents with wall mounted fluorescents
o $1,012 annual savings calculations for ASU ECM 1 predicted but the cost was high due to movement of the fixturing.
• Installation of wall mounted T8 lamps, occupancy sensors, and dimming ballasts o $1013 annual savings with 6.5 year payback for ASU ECM 2
The following group of Energy Conservation Measures shows significant or even excellent energy savings but do not fall into either of the above groups based on payback. These ECMs should not be discounted for payback reasons; rather they should be implemented on a case basis after careful consideration of all parameters and the benefits desired.
• Installation of daylight harvesting system for UNCC ECM 1 o Proper incorporation seems best suited to original designs and could be
difficult to retrofit in existing buildings. Potential sites must be carefully chosen.
Common themes
• Multiple comments were noted that end user buy-in is essential for program success. People want to be involved.
• Energy saving measures must constantly be revisited. o Many existing systems, most notably in building HVAC systems, already
had energy saving systems in place but were either deactivated or overridden completely or were not maintained properly.
o Occupancy sensors that were not checked for proper operation actually can negatively affect energy savings, user acceptance and credibility.
• Install occupancy sensors and dimmers where usage is appropriate and monitored for proper operation
o Circuits must be isolatable
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o Operation must be monitored o Users must be trained
Summary of Lessons Learned
• Identify all areas within State buildings where lighting is required to be on 7/24
for safety, security, or other reasons o Upgrade lighting to T8 technology
• All other lighting applications must be evaluated on a case basis for effectiveness of retrofitting with high efficiency lighting and lighting controls
o Replace incandescent lamps with T8s where appropriate o Replace T12s with T8s, where the expenditure cost is allowed to meet
reasonable payback o Occupancy sensors should be installed where practical
Use dual technology sensors for best results Employ experienced technicians for proper installation Train the local facilities staff for maintenance so they can make
adjustments Get user buy-in, the people that occupy the spaces must understand
and accept the controls • Upgrade all steam radiators with thermostatically controlled steam valves • Install lab hood ventilation controls in our State operated laboratories
o Design the exhaust systems to achieve the most effective use of the automation equipment
o Follow up with requirements for health and safety • Fix our HVAC systems
o Schedule AHUs to cycle off during periods of no occupancy, where practical and where the safety and health requirements are not in conflict.
o Repair HVAC system components that are designed to save energy and that have fallen into disrepair or have been shut off
o Install VFDs on HVAC systems where practical o Tune existing DDC controls for maximum system efficiency
• Enforce the general rule “If it isn’t being used, turn it off” o Automate systems to accomplish this rule wherever possible o Educate our State building occupants to comply with this simple but
effective rule
All of the Energy Conservation Measures contained within this report are successes. Saving North Carolina’s energy resources is an effort that will take on many forms, each uniquely tailored for its specific function; however, these efforts are all united in the common goal of applying existing technology to reduce energy consumption. All of the ECMs demonstrated a reduction in energy consumption. The expenses in applying this technology, both material and labor, make some of the ECMs less desirable for retrofit
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purposes. Other ECMs incurred very small expense and yielded great energy savings results. So it is clear that economics alone do not define success or otherwise. But the lessons from these ECMs should be learned and the efforts should be continued and applied on a broader scale throughout North Carolina’s State facilities.
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Acknowledgments
The State Energy Office would like to thank the participants in the ECMs described within. Without their hard work and dedication to the conservation of North Carolina’s energy resources, this study would not have been possible. NC A&T State University – Dr. H. Singh NCSU – Dr. Herb Eckerlin Appalachian State University – Dr. Jeff Tiller UNC – Charlotte – Dr. D. Brentrup
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NC A&T State University – Greensboro, NC Contact: Dr. H. Singh – [email protected]
List of NC A&T State University ECMs
1. Replacement of Existing Valves with Thermostatic Control Valves on Steam Radiators
2. Installation of Lighting Controls and High Efficiency Lighting in McNair
Hall 3. Installation of Variable Air Volume Control Valve on Laboratory Fume
Hood in Carver Hall
4. Demonstration and Verification of Energy Savings Available through HVAC Upgrade in a University Building
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1. NC A&T State University ECM – Replacement of Existing Valves with
Thermostatic Control Valves on Steam Radiators Overview The primary objective of this study was to determine the energy savings potential from replacing control valves and steam traps in steam radiators with thermostatically controlled valves. 10 radiators within Carver Hall of NC A&T University were fitted with these devices. Steam enters the radiator, condenses and transfers its heat to the space. The valves on the radiators in this study were stuck in the “open” position allowing steam to flow through the radiators at full rate regardless of the outside air temperature. The ¾ inch Thermostatic Control Valves manufactured by Macon Control Valves were used in this test. The valve regulates steam flow based on outside air temperature. Additionally, ½ inch steam traps on each of the radiators were replaced. Condensation flow rate was measured before and after this ECM in order to calculate energy savings. <LINK to Carver Hall Radiators Final Report.pdf> Conclusions and Recommendations Conclusion 1. Thermostatic control valves on steam radiators provide a remarkably
short payback of 17 days. The net savings of the project are estimated to be 3 million Btu per day or $865 / month for the 10 radiators in this study. This calculation assumes $7.46/106 Btu and 80% boiler efficiency. The expenditure is approximately $50 per radiator, $40 for parts and $10 for labor. Additionally, this ECM significantly improved the comfort level for the occupants by providing a more controlled, constant temperature environment.
Recommendation: Implement this ECM in all state-operated facilities that use
steam radiators.
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2. NC A&T State University ECM – Installation of Lighting Controls and High
Efficiency Lighting in McNair Hall Overview The primary objective of this study was to determine the energy savings potential from use of high-efficiency T8 lamps as well as occupancy sensors. An area equal to approximately 10% of McNair Hall at NC A&T University was used for this study. <LINK to McNair Hall Lighting Final Report.pdf> Conclusions and Recommendations Conclusion 1. This ECM is similar to the first two ECMs above. This study has
concluded that there would be a 2.91 year payback using conservative assumptions. In reality, the study concluded that occupant training as well as adjustments of the sensors after installation could lead to additional savings.
Recommendation: Replace all incandescent and low efficiency fluorescent
lighting with high efficiency lighting in state operated buildings. Evaluate and implement occupancy sensors areas that are suitable for such.
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3. NC A&T State University ECM – Installation of Variable Air Volume
Control Valve on Laboratory Fume Hood in Carver Hall Overview The laboratory hoods in Carver Hall were all constant air volume by-pass hoods. This project was designed to test the feasibility of converting a constant air volume by-pass hood into a variable air volume fume hood and to observe any associated energy savings. Laboratory hood air flow volumes are subject to industry standards and by OSHA regulations. The variable air volume fume hood is designed to detect the presence or absence of an operator within the work area of the hood and to adjust the air flow accordingly, thus saving energy from the reduced amount of conditioned air (heated or cooled) unnecessarily exhausted. Lower air flow rates, to a limit, are considered acceptable for unattended work areas. The variable air volume fume hood system incorporates an adjustable air valve, sash and zone presence sensors, and associated monitoring and control equipment. <LINK to Carver Hall Hood.pdf> Conclusions and Recommendations Conclusion 1. Measured results indicate an average of 672 CFM savings in average
airflow being exhausted. Based on data for unit CFM heating and cooling costs for Greensboro ($2.54/CFM), annual energy savings of $1,706 were calculated for one hood. This calculation does not take into consideration the electrical energy savings from the reduced fan loads. The simple payback period of 5.8 years is based on a $10,000 equipment expenditure. A quicker payback may be realized with a redesign, or reallocation of equipment, which combines multiple hoods into an exhaust header with a variable air volume exhaust fan.
Recommendation: Based on the modest 5.8 year payback, an additional study
should be launched to test the recommendations of the study to combine multiple hoods into a common header. Additionally, monitoring equipment should be installed to capture the electrical energy savings from reduced fan loads.
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4. NC A&T State University ECM – Demonstration and Verification of Energy
Savings Available through HVAC Upgrade in a University Building Overview The energy crisis of the seventies brought about a change in building designer’s thinking about energy conservation. As a result, building envelops were constructed tighter and the fresh air introduced was decreased. The eighties ushered in the “sick building” and in response designers and manufacturers developed designs, equipment and control strategies to improve the air quality. These early control systems were complicated and difficult to calibrate. Over the years, maintenance of these systems has deteriorated to the point where they have become mostly disabled. This ECM was designed to measure the energy savings from updating the motor and controls on one air handling unit (AHU) in McNair Hall on the campus of NC A&T University. Additionally, this ECM captures improvements in the building air quality by measuring CO2 levels before and after this ECM. In all, four components were specified for this experiment – AHU#1 installation of a high energy efficiency motor driving the fan, installation of a variable frequency drive (VFD) for the motor, installation of digital controls to operate control sequences, and installation of a carbon dioxide sensor to control fresh air to the building. <LINK to McNair Hall AHU.pdf> Conclusions and Recommendations
Conclusion 1. Daily average demand for the AHU before the installation of the new motor and VFD was 23.83 kW. After the installation, this number dropped to 6.9 kW, which can result in 12,190 kWh per month energy savings or $731 savings in the building electricity bill. Similarly, the demand for McNair dropped from 387 kW to 237 kW, which shows the saving of 108,000 kWh per month or $6,480. Furthermore, the new system and retrofit improved the quality of the indoor air by reducing the CO2 level from 2,900 PPM to 1,100 PPM.
Recommendation: Obtain expenditure data and calculate payback timeframes from implementing this ECM. Obtain data from the current HVAC Controls tune-up program to compare results. The current tune-up program allows only for existing system improvements and does not allow for system component replacements as this ECM performed. Comparisons of results will help us understand the true value of this ECM.
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Appalachian State University – Boone, NC Contact: Dr. Jeff Tiller – [email protected]
List of Appalachian State University ECMs
1. Lighting retrofit in Health Promotions area of Varsity Gym 2. Install T8 Lamps and Occupancy Sensors in Kerr Scott Hall rooms 167 and
207
3. Install Variable Frequency Drives for CAP Building HVAC System
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1. Appalachian State University ECM – Lighting retrofit in Health Promotions
area of Varsity Gym Overview The primary objective of this study was to determine the energy savings potential from converting incandescent ceiling mounted lighting to wall mounted fluorescent lighting. Wall mounting brings the light source closer to the occupants, therefore reducing the necessary candle power required to sufficiently light the area. Additionally, converting from incandescent to fluorescent provides another opportunity for total energy savings from this single retrofit <LINK to USI final report (Appalachian State).pdf> Conclusions and Recommendations Conclusion 1. Replacing existing ceiling mounted incandescent lights with wall-mounted
fluorescent lighting reduces electrical consumption as well as improves lighting levels for increased occupant efficiency, safety, and comfort. Annual electrical savings of $1,012 were calculated from implementation of this ECM in the area that was studied.
Recommendation: Implement this ECM in all state-operated facilities.
Evaluate areas with high ceilings for opportunities to lower the lighting fixtures from the ceiling to the walls so they are closer to the target areas.
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2. Appalachian State University ECM – Install T8 Lamps and Occupancy
Sensors in Kerr Scott Hall rooms 167 and 207 Overview The primary objective of this study was to determine the energy savings potential from installing high efficiency T8 lamps, occupancy sensors, and dimming ballasts. One room was fitted with all three of the above components while another was fitted with only the T8 lamps. <LINK to USI final report (Appalachian State).pdf> Conclusions and Recommendations Conclusion 1. Replacing older fluorescent fixtures with T8 lamps and installing
occupancy sensors where appropriate can save money. Annual savings of $463 in room 167 and $1,013 for room 207 were calculated from measured data. Room 167 showed a dramatic 60% decrease in energy usage from the use of T8 lamps plus occupancy sensors as well as dimmable ballasts. Room 207 showed a more modest 28% decrease in energy usage from only the retrofit to T8 lamps.
Recommendation: Install T8 lamps, occupancy sensors, and dimmable
ballasts in all state government buildings where inefficient lighting currently exists. Studies should be performed on an area-to-area basis to determine suitability of occupancy sensors. User buy-in is critical to the success of this ECM.
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3. Appalachian State University ECM – Install Variable Frequency Drives for
CAP Building HVAC System Overview The primary objective of this study was to determine the energy savings potential from installing variable frequency drives for the CAP building HVAC system air handlers. <LINK to USI final report (Appalachian State).pdf> Conclusions and Recommendations Conclusion 1. Preliminary estimates of energy savings are in the range of $10,000 per
year, providing about a four year payback for the investment. This project suffered significant delays, thus conclusive data had not been obtained at the time the report was written.
Recommendation: The preliminary estimates show a desirable payback
period. Further studies should be made to solidify these estimates.
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NC State University – Raleigh, NC Contact: Dr. Herb Eckerlin – [email protected]
List of NC State University ECMs
1. Replace Incandescent Lights in Hallway with Compact Fluorescents, Carmichael Gymnasium
2. Install T8 Lamps and Occupancy Sensors in Classroom 1402, Broughton
Hall
3. Install T8 Lights with Dimming Control and Occupancy Sensors in Rooms 2209 and 2210, College of Textiles
4. Reduce Hallway Lighting from 4 Lamps to 2 Lamps, Research IV on
Centennial Campus 5. Install Occupancy Sensors in Classrooms 3216, 3218, and 4217 in Broughton
Hall 6. Move Occupancy Sensor to Prevent False Triggers, Broughton Room 2211 7. Install Occupancy Sensor in Classroom 220, Dabney 8. Reactivate Glycol Heat Exchanger System, Carmichael Gymnasium 9. Program AHU Fans to Deactivate During Inactive Periods, older sections of
Carmichael Gymnasium
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1. NCSU ECM - Replace Incandescent Lights in Hallway with Compact
Fluorescents, Carmichael Gymnasium Overview The hallway and bathrooms behind the older swimming pool are lit with 29 – 100 Watt incandescent lamps. These lamps are left on twenty-four hours per day, 365 days per year for security reasons. Replacing these lamps with compact fluorescent lamps will reduce power (i.e., kW demand) and energy use. The result is lower electrical costs. Electrical current was not monitored for this space, since the lights are on continuously. In addition to the electrical cost savings, there are lamp cost savings, as well. <LINK to NCSU Carmichael Gymnasium CFLs.doc>
Conclusions and Recommendations Conclusion 1. Replacing incandescent lights (operating continuously) with compact
fluorescent lamps is an excellent energy conservation measure (i.e., 3 month payback for lights operated continuously).
Recommendation: Implement this ECM at all state-operated facilities. Conclusion 2. It is important to note that light operating time is an important variable
(e.g., replacing lights operated 8 hours per day rather than continuously will have a somewhat longer payback period).
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2. NCSU ECM - Install T8 Lamps and Occupancy Sensors in Classroom 1402,
Broughton Hall Overview The existing four lamp F40T12 fluorescent fixtures with glazed covers were replaced with three lamp F32T8 lamps with open lenses. Broughton classroom 1402 was lit by twenty-one four lamp, F40T12 fixtures. The lighting was divided into four separate circuits, so that some intermediate lighting levels could be obtained. The lights in the space typically operated six to seven days per week and were often left on overnight, even when the room was empty. Upon recommendation of the NCSU USI team, the four lamp fixtures were removed and replaced with three lamp T8 fixtures with an open lens. The number of circuits was reduced from four to two. To address the overnight and weekend problem, two occupancy sensors were installed. <LINK to NCSU Broughton Hall T8 Lamps and Occupancy Sensors.doc > Conclusions and Recommendations Conclusion 1. Replacing existing 4 lamp T12 fixtures with 3 lamp T8 open fixtures has a
payback in excess of 10 years and is not cost effective in existing buildings (unless perhaps under a Performance Contracting scenario). This ECM is most appropriate for new construction.
Recommendation: Upgrading a lighting system comprised of 4 lamp T12
fixtures with 3 lamp T8s is not recommended in existing buildings.
Recommendation: Using 3 lamp T8 open fixtures is most appropriate for new
construction. Conclusion 2. Even the inclusion of occupancy sensors does not make this ECM
attractive.
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3. NCSU ECM - Install T8 Lights with Dimming Control and Occupancy
Sensors in Rooms 2209 and 2210, College of Textiles Overview Four classrooms in the College of Textiles (COT) were initially considered for lighting retrofit to replace four-lamp T12 fixtures with three-lamp T8 fixtures with electronic ballasts. Rooms 2208 and 2210 are identical in size, arrangement, and lighting power. Similarly, rooms 2209 and 2211 are identical. Lighting in each room is provided by ten or eleven fluorescent fixtures, each with T12 lamps and a magnetic ballast. Upon recommendation of the NCSU USI team, an outside contractor was hired to install (1) the new 3-lamp T8 fixtures with dimmable electronic ballasts, and (2) the ultrasonic occupancy sensor controls in Rooms 2209 and 2210. Rooms 2208 and 2211 were left intact to serve as the control rooms. <LINK to NCSU College of Textiles.doc >
Conclusions and Recommendations
– This project was not cost effective. Conclusion 1. Installing T8 lights with dimming controls and occupancy sensors
involves a significant technology upgrade that will affect how the professors use the classroom.
Recommendation: Making a significant technology upgrade on an existing
classroom should only be attempted in selected instances, and only with the complete buy-in of the people who will be teaching in the classroom.
Conclusion 2. Many of these advanced classrooms are managed by a technology
“expert.” Recommendation: This person should be involved with the project from the
beginning (i.e., when it is being conceived). Recommendation: A Training Program for faculty and staff in the use of the
system should be part of the entire technology upgrade. This is an important role for the “technology expert.”
Conclusion 3. The selection of an experienced contractor is essential. Recommendation: Check to see if the contractor has experience with
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installing the equipment to be used on the project. Also check if the work will be done by his people or by a subcontractor.
Conclusion 4. Occupancy sensor type and location are very important. A few
malfunctions will cause the instructors to become disillusioned very quickly.
Conclusion 5. Fine-tuning the occupancy sensor system can become very time-
consuming. Recommendation: We recommend “Dual Technology” occupancy sensors
(i.e., sensors that utilize a combination of infrared and ultrasonic principles). These sensors work better and require less adjustment after installation.
Conclusion 6. A technology upgrade that involves new T8 lights, with dimming
controls and occupancy sensors can become expensive very quickly.
Recommendation: The type of technology upgrade implemented at COT may
make the most sense if it is incorporated in new construction.
Recommendation: It is recommended that an educational institution
identify/determine a standard type of equipment to be used across campus to minimize the confusion that can be created by having to learn several control platforms.
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4. NCSU ECM - Reduce Hallway Lighting from 4 Lamps to 2 Lamps,
Research IV on Centennial Campus Overview The hallways are lit with four lamp fixtures (with two electronic ballasts) that use a combination of T12 and T8 lamps. Lighting is more than adequate and reducing the number of operating lamps per fixture from four to two is a distinct possibility. The lights are often left on all night and through the weekends for safety reasons. The tenants come and go at different hours. Deactivating the hall light switch would mean total darkness for anyone leaving his or her office. Compromising the safety of personnel for energy savings makes total deactivation an unacceptable option. The NCSU USI staff spent several hours with a ladder and a cart removing all T12 lamps and installing two T8 lamps in each fixture. <LINK to NCSU Research IV Centennial Campus.doc>
Conclusions and Recommendations Conclusion 1. Reducing hallway lighting from 4 fluorescent lamps to 2 resulted in a 32
percent reduction in hall lighting energy usage. Conclusion 2. Hallways in our commercial and institutional buildings are one of the
areas where lighting is not controlled (i.e., lights are often left on around the clock).
Recommendation: Developing a lighting strategy (to reduce hall lighting) in
the buildings on a university campus is an ECM that deserves more attention…. and can yield substantial savings.
Recommendation: Every organization/department should develop a policy on
necessary lighting in hallways. Personnel safety is an important factor to consider.
Conclusion 3. Many hallways have more than sufficient lighting.
Recommendation: Reducing from 4 lamps to 2 lamps per fixture is a simple cost effective approach and yields over 30% savings in hall lighting. If the new lighting level is satisfactory, an additional 15% savings can be realized by disconnecting the ballast that is no longer in use. This is not a cumbersome task, but would require the services of an electrician.
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Conclusion 4: Reducing the lamps per fixture is simple and straightforward, does not
require much advanced planning with others, and can be implemented quickly.
Comment: In older buildings, some of the hall lights may be on a separate
emergency generator circuit. If that is the case, it may be possible to control the main hall lights with an occupancy sensor(s) and simply leave the emergency lights on all the time.
Recommendation: Evaluate (as an M&V project) the feasibility of using emergency circuits for backup hall lighting so that the remainder of the hall lights can be controlled by occupancy sensor(s).
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5. NCSU ECM - Install Occupancy Sensors in Classrooms 3216, 3218, and
4217 in Broughton Hall Overview Broughton classrooms 3216, 3218, and 4217 are lit by F40T12 fixtures. The lighting in each room is divided into at least two separate circuits, so that some intermediate level of lighting can be obtained. The classrooms are typically used from 8 am until about 6 pm, 5 days per week. Weekend and evening occupancy is typically sparse, unless there is some planned University event. Upon recommendation of the NCSU USI team, occupancy sensors were installed in all three classrooms. <LINK to NCSU Broughton Hall Occupancy Sensors.doc> Conclusions and Recommendations Conclusion 1. The installation of occupancy sensors in Broughton 3216 and 3218
reduces the lighting energy use in these rooms by 57%.
Recommendation: It is recommended that the use of occupancy sensors be expanded all classrooms in the UNC system.
Conclusion 2. Occupancy sensors are the ECM of choice to reduce the lighting costs in
the classrooms of our universities and community colleges. Conclusion 3. The factors that affect the cost of installing occupancy sensors are:
The number of power sources to be controlled, The number of occupancy sensors required for coverage, The number of lights to be controlled, The type of surface to which the sensor can be mounted, and The length of wire and conduit required.
Conclusion 4. Occupancy sensors extend the life of the fluorescent tubes, thus reducing
the lighting maintenance cost. This should be included in the economic analysis of the ECM.
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6. NCSU ECM - Move Occupancy Sensor to Prevent False Triggers, Broughton
Room 2211 Overview Broughton classroom 2211 is lit by eighteen three lamp, F32T8 fixtures. The lighting is divided into two separate circuits, each connected to an occupancy sensor. One sensor is located near the front of the classroom, which controls just a few lights. The other sensor is located at the back of the classroom in direct line with the main door for egress and controls the other fifteen lights. The sensors work well in deactivating the lights when the classroom is not occupied. However, the sensor at the rear of the classroom activates whenever someone walks by in the hallway outside the room. Since the hallway is a frequently used corridor, the lights do not shut off as much as they should, wasting energy. <LINK to NCSU Broughton Rm2211.doc> Conclusions and Recommendations Conclusion 1. Improperly located occupancy sensors can actually cause an increase in
lighting energy usage. Conclusion 2. Relocating occupancy sensors is generally inexpensive and should not be
postponed. Recommendation: Staff must be alert to identify situations where occupancy
sensors are operating improperly.
Conclusion 3. This ECM can prove to be very beneficial.
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7. NCSU ECM - Install Occupancy Sensor in Classroom 220, Dabney
Conclusions and Recommendations Conclusion 1. The installation of occupancy sensors in Dabney 220 was one of the first
ECMs selected under the USI Program and, in retrospect, was not a particularly good demonstration project – for the following reasons:
i. Room usage is not representative of campus usage, as a whole. ii. The circuits that control the lights in the classroom could not be
isolated (i.e., they also power lights in adjacent offices). iii. The installation of the current transformers (CTs) was not
coordinated with MAE Staff working on the USI Project.
Comment: The monitored classrooms in Broughton Hall serve as a much better example of the potential savings through the use of occupancy sensors.
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8. NCSU ECM - Reactivate Glycol Heat Exchanger System, Carmichael
Gymnasium Overview The locker rooms at Carmichael Gymnasium were not originally air-conditioned. Large volumes of air (about 140,000 cfm) were drawn into the space and then exhausted. Air conditioning was added to the area about fifteen years ago and the exhaust air volumes greatly reduced. A system of heat exchangers was also installed to transfer energy between the exhaust air and the incoming fresh air. In the winter, heat from the exhaust air is absorbed by glycol flowing in coils in the common exhaust duct. The glycol is then pumped around to several heat exchangers installed in the fresh air inlet ductwork of the air-handling units. The glycol conditions the incoming air, thereby reducing the heating load on the hot water coils. In the summer, the system would operate to pre-cool incoming fresh air using the relatively cool and dry exhaust air. The system worked for a time, but there were problems with glycol leaking from the heat exchangers and the valves fell into disrepair. As a result, the entire system was shut down and essentially forgotten. <LINK to NCSU Carmichael Gymnasium Glycol Heat Exchanger .doc> Conclusions and Recommendations Conclusion 1. High turnover in maintenance personnel may affect the
accuracy of the HVAC and controls information available at the facility.
Recommendation: Go through a facility carefully to insure that all equipment
is identified and understood. In this case, the existence of the runaround heat exchanger was discovered only after careful inspection of all HVAC equipment.
Conclusion 2. The absence of flow measurement equipment may make it difficult
to calculate the potential savings for a piece of equipment. Conclusion 3. Regular maintenance checks are important to insure that the
runaround system is operating properly (e.g., checking on glycol fluid level, on heat exchanger cleanliness, filters replacement, etc.).
Conclusion 4. The savings from heat recovery is not constant but will vary with
the season. Conclusion 5. It was difficult to get an accurate measure of the effectiveness of
this ECM.
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9. NCSU ECM - Program AHU Fans to Deactivate During Inactive Periods,
older sections of Carmichael Gymnasium Overview The basketball courts in the older section of Carmichael Gymnasium are conditioned by eight air handling units (AHU) that are supplied with chilled water and steam from the campus system. These air handling units were being operated twenty-four hours per day, seven days per week. Upon recommendation of the NCSU USI team, maintenance personnel reprogrammed the energy management system to deactivate the fans during off-periods - specifically, from 11 pm to 6 am. <LINK to NCSU Carmichael Gymnasium Deactivate AHU.doc> SUMMARY: Reprogramming the operation of the AHUs in the older section of
Carmichael Gymnasium reduces their energy use by 43 percent and saves $9,500 per year.
General Conclusion Large multi-use facilities such as gymnasiums, field houses, auditoriums, etc. are large energy users and often present opportunities for significant energy savings. Areas deserving particular attention are:
• Types and wattage of lights used, • Lighting use schedule, • Control of the AHUs and associated chilled water and steam, • Ventilation makeup air schedules, • Use of economizer schedules.
Conclusions and Recommendations Recommendation 1: Because of turnover in personnel, recognize that institutional
memory may be limited. Ask lots of questions. Check out possible leads.
Recommendation 2: The first step is to determine the operating schedule for the AHUs.
Check with maintenance about this operating schedule (if it exists) and the existence of an energy management system. At the same time, check with facility personnel about how the space is used. Then begin to formulate a strategy for setting a new AHU operating strategy. Recognize that finding the “right” schedule is a trial and error process and that you may have to do some experimentation along the way.
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Note: At the subject site, an energy management system did exist, but was not being used. In this case, reprogramming the AHU units solved the problem.
Recommendation 3: If an energy management (i.e., control) system does not exist,
consider installing a data logging system (CTs and Hobos) to get a sense of the AHUs operating schedule and energy use profile. Gather data for at least two weeks, so that weekday and weekend use can be evaluated. As indicated in Rec. 2 above, information about occupancy schedules and load is important in determining proposed schedules and potential savings.
Recommendation 4: It is important to discuss the problem and its resolution with top
management (e.g., Facility Manager) to insure that all operational perspectives have been considered. It is important to keep them in the loop and get their buy-in.
Recommendation 5. If an energy management system is involved in solving this type of
problem, please check to see that proper training in its operation is made available to the maintenance people.
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UNC – Charlotte, NC Contact: Dr. D. Brentrup – [email protected]
UNC Charlotte ECM
1. Atkins Library Daylight Harvesting
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1. UNC Charlotte ECM – Atkins Library Daylight Harvesting
Overview The primary objective of this study was to document the effectiveness of a daylight harvesting system placed in the Atkins Library at the University of North Carolina at Charlotte. The daylight harvesting system selected was a closed loop Lutron “Radio Touch System” including controller with continuous dimming ballasts and daylight sensor. <LINK to Atkins Final Report.pdf> Conclusions and Recommendations Conclusion 1. This ECM demonstrates that dimming techniques are an effective method
of energy conservation. The study calculated a 40% annual efficiency increase is attainable with this ECM. The investigators concluded that “…the daylight harvesting system does conserve energy. And would mitigate an estimated 30 tons of CO2 from NC skies.”
Conclusion 2. “A comparative analysis of the data collected before and after the
installation of the system shows as much as a 50% reduction in lighting demand during the daylight hours has been obtained. The data suggests that the ECM can be an effective energy conserving building strategy. However, other critical factors observed over the period of the study; that are both directly and indirectly associated with the installation of the ECM, will have a measurable influence on the interpretation of the terminology that describes an ‘efficient operation’.”
Recommendation: Implement this ECM where practical. Guidelines should be established for economical implementation.
