Table of Contents. Executive Summary Site and Unit Background Chiller Chiller Appendix... 11

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2 Table of Contents Executive Summary... 3 Site and Unit Background... 5 Chiller Chiller Appendix A Vidaris Company 2

3 Executive Summary New York Blood Center s facility in Long Island City, NY is a two-story 75,000 square foot building that serves as a blood bank as well as a processing laboratory. Two identical ton rooftop AAON aircooled chillers were comprehensively monitored for energy use to examine the immediate effectiveness of Ener.co s treatment process on condenser coil assemblies. The treatment process involves a thorough cleaning of the coil assembly, mechanical realignment of the fins (when necessary), preparing all coil surfaces for coating, and coating the coil-fin assembly with a ultra-thin layer of a proprietary anticorrosive chemical that claims to prevent an increase in energy consumption over time caused by the degradation of the coil surface. In order to differentiate between the effects of treatment with or without the coating, one chiller (chiller 1) underwent through the full Ener.co process while the other chiller (chiller 2) received a partial treatment where it received all the steps in the process mentioned above except that it was not coated with the anti-corrosive chemical. The results of the year-long before and after evaluation demonstrate that the full Ener.co treatment process can immediately reduce the energy use of a well-maintained five-year-old unit. Though the chillers run in a lead-lag sequence, chiller 1 has predominately served as lead in the past. While chiller 2 maintained its off-the-shelf performance, chiller 1 has been exposed to more wear and tear, and therefore posed a greater potential for improvement. Chiller 1 experienced the benefit of a 10% reduction in power draw (2.3 kw) while chiller 2 experienced a reduction of 4% (0.7kW) for similar weather conditions. Cooling capacity of each chiller was monitored alongside power draw and is expanded on in the next section. The findings are summarized in the following figures 1 and 2. The long-term benefits of the full treatment will be realized by the facility and verified by future monitoring of the two chillers. Figure 1 Using normal facility operation of chiller 1 alone and electricity cost of $0.22 per kwh in NYC, the expected first year energy savings will be approximately $4,000. A Vidaris Company 3

4 Further investigation was undertaken into the energy consumption of the compressors and fans of chiller 1 to disaggregate the unit s overall energy reduction and breakdown the savings to its constituent components. Of the total reduction of 10%, 89% of this was attributed to compressor power reduction and the other 11% to fan power reduction. Figure 2 A Vidaris Company 4

5 Site and Unit Background The New York Blood Center s facility in Long Island City, NY serves as a blood bank as well as a processing laboratory. The principal components in the system being evaluated are the two 2006, 60- ton AAON air-cooled glycol chillers (model number LL AA0A-000) serving assorted refrigeration loads throughout the facility. While only one chiller is operational at any given time, the second exists for system redundancy. Figure 3 The units were monitored from the fall of 2010 through the fall of The units were treated (again, with or without the coating) during the end of the summer of The lead-lag sequence of the chillers was swapped both before and after the Ener.co process to allow for the comparison of periods of operation for each unit during a wide range of outside weather conditions. True-power calibrated data loggers on each unit recorded the kilowatt use for five minute average sampling intervals. Based on the data observed, it appears that the system is oversized. Although each chiller has four 15- ton Copeland scroll compressors, one of these four was able to meet the cooling load throughout the vast majority of the monitoring period with frequent cycling. Warmer outside temperatures called for the operation of two compressors to meet the load, though this study focused on the operation of a single compressor for each chiller at a time. Unlike other Ener.co demonstration projects involving direct expansion coils, measuring the cooling capacity of the glycol chillers was more involved. The thermal inertia of a fluid cooler in this project (versus a direct expansion air cooler) and the frequent cycling of the compressor resulted in data indicating no conclusive effect on the units cooling capacity both before and after the treatment. Since, however, there was a sizeable reduction in power draw, the result was a clear improvement in chiller performance. Refer to the appendix for more information on the specific measurement methodology. A Vidaris Company 5

6 Chiller 1 The condenser coil assembly of chiller 1 was restored and treated. The following figures 4 and 5 depict the average reduction in power draw for chiller operation of two fans and one compressor during similar weather conditions: Figure 4 Catalog Before After % Reduction Total kw % Compressor kw % Fan kw % Controls kw Figure 5 It is observed that the energy savings of treatment are distributed between compressor and fan power with the compressor power responsible for the majority of the savings. A Vidaris Company 6

7 The following figures 6, 7, and 8 represent data points that have been filtered to show only steady-state operation during similar weather conditions with the periods of rain removed. There is a clear trend observed in the unit s total, compressor, and fan power across a wide array of outside air temperatures. Figure 6 A Vidaris Company 7

8 Figure 7 Figure 8 A Vidaris Company 8

9 Chiller 2 The condenser coil assembly of chiller was treated without the coating. The following figures 9 and 10 depict the average reduction in power draw for chiller operation during similar weather conditions: Figure 9 Catalog Before After % Reduction Total kw % Figure 10 The following figure 11 represent data points that have been filtered to show only stead-state operation during similar weather conditions with the periods of rain removed. There is a clear trend observed in the unit s total power across a wide array of outside air temperatures. A Vidaris Company 9

10 Figure 11 A Vidaris Company 10

11 Appendix Methodology The lead-lag sequencing of chillers 1 and 2 were swapped periodically over the course of one year starting on October 18 th 2010 through November 4 th, The treatment took place on the week of September 19 th, Ample performance data was collected both before and after the treatment for both chillers for a wide array of outdoor weather conditions. The following test instruments were installed on both units: One (1) DENT data-logging electric power test meter to measure and record the total true power draw for the entire chiller; using four (4) clip-on voltage probes, and two (2) current transformers. One (1) Hobo data-logger and two (2) remote, surface-type temperature sensors on the intake and discharge of chilled glycol piping. One (1) Hobo data-logger and two (2) remote temperature sensors to measure and monitor the air temperatures at the intake and discharge of the air-cooled condensers. The following test instruments were installed on only the unit being fully treated (chiller 1): Two (2) additional DENT data-logging electric power test meter to measure and record the total true power draw for the first two compressors; using four (4) clip-on voltage probes, and current transformerss on 2 of the 3 legs. Eight (8) Hobo data-loggers with fifteen (15) current transformers to measure and record the current draw on each of the three (3) legs for each of the two (2) remaining compressors and three (3) and condenser fans. For components with current transformerswhere only amperage was measured, true power was calculated based on the following equation: where power factor was measured with a handheld clamp-on meter at various times during the experiment. An additional two (2) Hobo data-logger temperature sensors monitored the ambient air temperature and R.H.. An ultrasonic flow meter was installed on a horizontal section of the chilled glycol piping common to both chillers within the facility s mezzanine mechanical equipment room. A Vidaris Company 11

12 Metrics Chiller 1: Total Unit o Volts o Amps o Kilowatts Compressors 1 and 2 o Volts o Amps o Kilowatts Compressors 3 and 4 o Volts o Amps o Powerfactor Condenser Fans 1, 2, and 3 o Volts o Amps o Power factor Intake and discharge temperatures across glycol/refrigerant evaporator Intake and discharge temperatures across the condenser coil assembly Chiller 2: Total Unit o Volts o Amps o Kilowatts Temperatures & R.H. o Intake and discharge across glycol/refrigerant evaporator Common to both Chillers: Ambient outdoor temperatures and R.H. Chilled glycol flow rate A Vidaris Company 12

13 Monitoring Devices Onset HOBO type U12 data loggers with external temperature sensors and current transformers DENT Instruments ELITEpro power data loggers with split-core current transformers GE Panametrics PT878 ultrasonic liquid data logging flow meter Amprobe ACD-41PQ 1000A power quality clamp meter The circuit panels of chiller 1 are seen below in figure 14, with DENT data loggers and split-core current transformers sub metering the chiller s electricity usage. Figure 12 A Vidaris Company 13

14 Below is a representative sample of the well-maintained condenser coil surface of both chillers before the treatment: Figure 13 The chillers (numbered below) are located on the center of the facility s rooftop: Figure 14 A Vidaris Company 14

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