C&LM Programs VendingMiser Monitoring Project FINAL REPORT April 2001 Prepared for: Conservation and Load Management Department 66 Curtis Street New Britain, CT. 06052 Prepared by: The Nicholas Group P. C. 21 Greendale Ave Cromwell, CT. 06416
Table of Contents 1. Executive Summary... 1 1.1 Background... 1 2. Scope of Work... 3 3. Monitoring Description... 5 4. Results by Location... 6 APPENDIX... 1
1. Executive Summary 1.1 Background The control of the lighting in beverage vending machines is a possible energy savings measure since the lighting is enabled 24 hours per day and in some machines the lighting serves no useful purpose in overnight periods and other periods of low or no occupancy. The refrigeration system that keeps the product cold is cycled thermostatically, but there is no control of the lighting. Bayview Technology Group, Inc. has developed a device that controls the electric power of a typical vending machine based on a combination of occupancy in the immediate area of the machine and upon product temperature. The device consists of a control module electrically connected to a wall mounted occupancy sensor. The features of the control device, named Vending Miser TM, will turn the refrigeration and lighting in the machine off when there has been no motion sensed for 15 minutes. If there has been no motion detected for an extended period of time, the device will activate the machine electrically, cycling the refrigeration to maintain product temperature. Savings will be realized from reduced lighting hours of use and from cycling the refrigeration system. This study was commissioned to determine the level of annual energy savings (expressed as a value and a percent) that can be achieved by the installation of the VendingMiser on a sample of 6 beverage vending machines. Electrical energy will be monitored in the as is state of the six machines. Electrical energy of the machines, with the device installed, will also be monitored and the difference will help to determine the extent of the prospected energy savings. Six different machines with six distinctly different occupancy patterns were selected for monitoring. The monitoring was done while school was in session. A power monitor was connected to the machines for a period of 2 weeks prior to and 2 weeks after the Vending Miser device was activated. At each machine, pre and post power, adjacent temperature, and inside vending temperature was monitored. The results confirmed that the device would turn the vending machine off during periods of no occupancy, and that during overnight periods when there was expected to be no occupancy the machines were cycled on to maintain product temperature. PRE POST SAV % LOCATION KWH KWH KWH 1 198 148 49 25 2 186 103 83 45 3 147 43 103 70 4 109 49 60 55 5 143 133 9 7 6 186 117 69 37 Table 1. Page 1
The energy savings for the 2-week period for each of the six machines is summarized in the table above. Location # 3 had its sensor moved by an unknown party 3 days into the post-test. The machine cycled on the temperature override for the majority of the test time and this would account for the high value of energy savings. The savings attributed to the device vary from 7 to 45 % based on actual monitored data. The outlier with the sensor removed showed savings of 70%. Page 2
2. Scope of Work From the 600 machines installed in all different types of building at the University of Connecticut, a sample of 6 indoor vending machines was selected for monitoring. The sample included 2 machines in each category of area, those expected to have low, medium, and high hours of use, in different buildings at the University. The intent of the monitoring was to record power and temperature on an hourly basis for a minimum of two continuous weeks prior to installation of the VendingMiser. The VendingMiser controller would then be installed on the same machines and electrical energy and temperature would be recorded for a second continuous 2-week period. The Elite 4 power monitor, manufactured by Pacific Science and Technology, was used to monitor energy consumption (kwh). The load was single-phase load and a 20 amp CT was used to measure amperage. The monitor measured average amperage, voltage, power factor, and power consumption, recording the values for each 15-minute interval in the pre/ post time periods. A HOBO Pro Series temperature recorder, manufactured by Onset, was used to monitor temperature. Temperature measurements were recorded every 2 minutes. Temperature of the inside of the machine and in the immediate area of the machine were measured and recorded. The local Coca-Cola distributor provides and maintains the vending machines on the UCONN campus. There are 3 different types of machines in use on the campus distributing both Coke and Fruitopia products. The machines are manufactured by either Royal, Vendo, or Dixie Narco. All machines are rated at 120 volts. The Royal machines have full load nameplate amps of 12, the Vendo machines have nameplate amps of 10 amps, and the Dixie Narco machines have nameplate amps of 11 amps. The machines monitored at locations 1, 2, and 6 are provided by Royal. The machines at locations 3 and 5 are provided by Dixie Narco and the machine at location 4 is a Vendo machine. A description of the 6 locations follows. Location 1: A Fruitopia machine located in the Operations building. The building houses building operations and maintenance for the entire campus and is in operation 24 hours per day. Location 2: A Coca-Cola machine located in the Facility Engineering Building. The building houses offices that support facility and construction activities on campus. The office hours are 8a.m. to 5 p.m. Monday through Friday. Location 3: A Fruitopia machine located in the hallway of the Arjona Classroom Building. The building serves as a classroom building and is in operation 16 hours per day. Location 4: Page 3
A Coca-Cola machine located in the break room of the Brown Administration Building. The building, which is off campus and houses school administrative staff, is in operation from 8a.m. to 5 p.m. Monday through Friday. Location 5: A Fruitopia machine located in the hallway of the McMahon Residence Hall. The building is a multi story student residence and is occupied 24 hours per day. Location 6: A Poweraide machine located in the employee lounge of the Library Building. The area is occupied 16 hours per day. Locations 1 and 5 were considered to be areas of high traffic, 3 and 6 were considered to be of medium traffic, and 2 and 4 were considered low traffic. The degree of traffic was defined by the hours of occupancy of the area served by the machines. Page 4
3. Monitoring Description The monitoring equipment was initially installed on January 17, 2001. The power monitor was pre wired in a Nema one enclosure that also contained the current transducer. All that was required was to unplug the vending machine from the wall and replug it through the monitoring equipment. The Vending Miser control module and sensor was also installed at this time but were left inactive. School was in session during the entire monitoring period. At the time of installation, the vending machine was verified to have all electric components operating. These are the 2 fluorescent lamps in the door of the machine and the refrigeration equipment. Proper operation and electronic signatures of the components were recorded through the monitoring equipment. On Feb 13, 2001 the pre-data was all verified to be complete and was downloaded. This data represented the pre-time period of the experiment. The VendingMiser devices were connected at this time at all 6 locations. On March 2 nd, the post-data was collected. At this time, the monitoring equipment was removed, and the Vending Miser devices were left in place at all locations except for location 3. The occupancy sensor at this location had been tampered with and the data for this location was determined to be invalid. It appeared that the sensor was not vandalized, but just relocated to behind the vending machine so that it would not sense motion. The temperature of the product was maintained indicating that the system was still in operation. After reviewing the collected data, it was determined that the data from the period January 28, 2001 through and including February 10, 2001 was a continuous string and was used as the complete 2 weeks of pre-data. For the post-period, the data from the period February 15 through and including February 28 th was used. For the monitoring project, the occupancy sensors were installed in a temporary fashion by the use of Velcro and adhesive. It is strongly recommended that since the machines are in accessible locations, that the devices be permanently installed. The sensor cover can be removed and the device can be permanently attached to the wall. The control module is supplied with a mounting bracket that can be affixed to the wall behind the vending machine. The module should not be readily accessible. It is also recommended that the instructions be followed to assure the sensor is mounted correctly and is sensing expected traffic in the area. Page 5
4. Results by Location Location 1: This installation is in the Operation s Building. The building is in operation 24 hours per day. The machine is located in an alcove area off the main hallway. There is one other soda machine and a candy machine in the same alcove. The machine is a Royal model 660. The monitored data revealed that there was compressor operation in each of the monitored 15- minute intervals in the pre period. The machine consumption for the 2-week pre-case was measured at 197 kwh. In the post-case, there were intermittent intervals in which the unit electronics were turned off. For this type activity, the off periods were all in the overnight and weekend time periods as shown in location 1 post-graph. The machine consumption for the 2-week post-case was measured at 148 kwh. This represents a 25% savings based on monitored data for the 4-week period. Please see Location 1 graph in the Appendix of power per 15-minute interval versus time for the pre and post period. Since the location is in a 24-hour area with no shutdowns and occupancy during holidays, these savings are representative of yearly values for this type installation. The projected yearly savings for this installation is 1,279 kwh. The interior product space temperature was kept consistent between 37 and 38 during the day periods with no off times. During the overnight, when the machine cycled off due to no occupancy, the internal space temperature varied between 37 and 50. A plot of Pre/post interior temperature is presented in the Location 1temperature versus time graph in the Appendix. The space sensor measured a consistent range of 77 to 80 in the adjacent area. Location 2: This installation is in the Facility Engineering Building. The building is in operation one-shift hours per day with 12 holidays observed per year. The machine is located in a kitchenette area off the main hallway. There is one other soda machine and a candy machine in the same room. The machine is a Royal model 660. The monitored data revealed that there was compressor operation in each of the monitored 15- minute intervals in the pre-period. The machine consumption for the 2-week pre-period was measured at 186 kwh. Please see Location 2 graph in the Appendix of power per 15-minute interval versus time for the pre and post period. In the post-case, there were consistent intervals in which the unit electronics were turned off. The intervals included periods between 6 p.m. and 7 a.m. the following morning on weekdays and for the entire weekend. This is as expected for this type activity area. The machine consumption for Page 6
the 2-week post-case was measured at 103 kwh. This represents a 45% savings based on monitored data for the 4-week period. Since the location is in an office with no shutdowns and twelve holidays per year, the estimated annual savings for this installation are 2,284 kwh and 47% of baseline consumption. The adjustments were made by treating holidays as the same value of savings as weekend days. The interior space temperature was not recorded due to an incorrect placement of the logger in the machine. The space sensor measured a constant range of 85 to 90 in the adjacent area. There was no heating set back. Location 3: This installation is in the Arjona Classroom Building. The building is in operation 16 hours per day. There is light maintenance activity for 17 weeks per year that represents schools breaks. There is no activity on weekends. The machine is located in the hallway on the main floor. There is a second soda machine in the same area. This machine is a Dixie Narco model 501. The monitored data revealed that the compressor did not operate in each of the monitored 15- minute intervals in the pre-period. The machine consumption for the 2-week pre-case was measured at 147 kwh. Please see Location 3 graph in the Appendix of power per 15-minute interval versus time for the pre and post period. As mentioned earlier, the sensor was removed such that the post data was invalidated. There were however 3 days of uncontaminated operation. For this 3-day period, there were consistent intervals in which the unit electrioncs were turned off. These intervals included the period between 10:30 p.m. and 6:30 a.m. the following morning on the 3 weekdays of post-monitoring. This is expected for this type activity area. Extrapolating the 3-day data to 2 weeks provides for 89 kwh of post consumption. This represents a 39% savings based on interpolated data for the 4- week period. Since the location is in a classroom building with 17 annual weeks of low or no occupancy the annual savings based on the limited data are estimated to be 2,165 kwh or 57%. The adjustments were made by treating savings for low occupancy as the same value as weekend savings. The interior space temperature was kept consistent between 38 and 42 during the day periods with no off times. During the overnight, when the machine cycled off due to no occupancy, the internal space temperature varied between 38 and 50. A plot of post-interior temperature is presented in the Location 3 temperature versus time graph in the Appendix. The space sensor measured a consistent range of 75 to 80 in the adjacent area. Location 4: Page 7
This installation is in the Brown Building, which is an administration building located off the main campus. The building is in operation one shift per day, with 12 holidays observed per year. The machine is located in a kitchenette area on the second floor. There is a candy machine in the same room. The machine is a Vendo model 511. The monitored data revealed that the compressor did not operate in each of the monitored 15- minute intervals in the pre-period. The machine consumption for the 2-week pre-period was measured at 109 kwh. This machine consumed the least amount of power of all the machines monitored. In the post-case, there were consistent intervals in which the unit electronics were turned off. These intervals included periods between 6 p.m. and 7:30 a.m. the following morning on weekdays and for the entire weekend. This is expected for this type activity area. The machine consumption for the 2-week post-case was measured at 49 kwh. This represents a 55% savings based on monitored data for the 4-week period. Please see Location 4 graph in the Appendix of power per 15-minute interval versus time for the pre and post period. Since the location is in an office with no shutdowns and twelve holidays per year, the estimated annual savings for this installation are 1,551 kwh and 55% of baseline consumption. The adjustments were made by treating holidays as the same value of savings as weekend days. The interior space temperature was kept consistent between 36 and 38 during the day periods with no off times. During the overnight, when the machine cycled off due to no occupancy, the internal space temperature varied between 36 and 44. A plot of post-interior temperature is presented in the Location 4 temperature versus time graph in the Appendix. The space sensor measured a consistent range of 68 to 77 in the adjacent area. Location 5: This installation is in the McMahon dormitory. The building is occupied 24 hours per day. The machine is located in the second floor lobby. There is one other soda machine in the area. The machine is a Dixie Narco model 501E. The monitored data revealed that there was compressor operation in each of the monitored 15- minute intervals in the pre-period. The machine consumption for the 2-week pre-case was measured at 143 kwh. In the post-case, there were few intervals in which the unit electronics were turned off. The machine consumption for the 2-week post-case was measured at 133 kwh. This represents a 7% savings based on monitored data for the 4-week period. Please see Location 5 graph in the Appendix of power per 15-minute interval versus time for the pre and post period. Since the location is in a dorm building with 17 annual weeks of low or no occupancy, the annual savings based on extrapolated data are 806 kwh or 22%. The adjustments were made by treating energy consumption for low occupancy periods as the same value as the observed intervals with the soda machine off. Page 8
The interior space temperature was kept consistent between 38 and 40 during the day periods with no off times. During the overnight, when the machine cycles off due to occupancy, the internal space temperature varied between 38 and 50. A plot of post-interior temperature is presented in the Location 5 temperature versus time graph in the Appendix. The space sensor measured a range of 50 to 90 in the adjacent area. Since the machine is located by the door, the range of temperatures is as expected. Location 6: This installation is in the Library employee lounge. The building has annual operation that reflects activities on campus. There are extra hours for exam periods and lighter hours for summer and vacation periods. The machine is located in a kitchenette area on the main floor. There is a second soda machine and a candy machine in the same room. The machine is a Royal model 660. The monitored data revealed that the compressor operated in each of the monitored 15-minute intervals in the pre-case. The machine consumption for the 2-week pre-case was measured at 186 kwh. Please see the Location 6graph in the Appendix. In the post-case, there were consistent intervals in which the unit electronics were turned off. These intervals included periods between 10 p.m. and 5:30 a.m. the following morning on weekdays and for the entire weekend. This is expected for this type activity area. The machine consumption for the 2-week post-case was measured at 117kWh. This represents a 35% savings based on monitored data for the 4-week period. Please see Location 6 graph in the Appendix of power per 15-minute interval versus time for the pre and post period. Since the location is a library, there are periods during the year when there is little activity in the building. There are also periods such as exam week when there are extended hours. Making adjustments to the monitored data to reflect these use patterns, the estimated annual savings were calculated to be 2,136 kwh and 44%. The adjustments were made by identifying intervals of data that would represent the defined use patterns. The interior space temperature was kept consistent between 35 and 37 during the day periods with no off times. During the overnight, when the machine cycles off due to occupancy, the internal space temperature varied between 35 and 44. A plot of post-interior temperature is presented in the Location 6 temperature versus time graph ins the Appendix. The space sensor measured a constant range of 70 to 80 in the adjacent area. Page 9
New Construction Program Refrigeration Study-Final Report APPENDIX A-1