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Click on the name of any project to see further details regarding the use of this technique, strategy, or technology on the project.
 
Ice storage
 
  Project County Ice storage Docs
 1  North Johnston High School Johnston North Johnston High uses 9 Calmac Ice Storage tanks to supplement its two 100-ton Trane air-cooled Series R screw chillers that reduce the KW load during the peak electricity demand hours from 10 AM to 2PM. Without the ice system, cooling would require 300 tons of chiller to condition the school. The KW difference is 130 load, an upfront savings about $635 a month on the KW peak. With the SGS-TOU rate from its electric supplier, CP&L, an additional monthly average of $1,192 is saved on the electrical bill for a total yearly savings at this school of $29,565.80 for the 118,465 square feet of conditioned space. There is little upfront cost for the system as compared to a conventional chiller unit, as the inclusion of ice storage in the system allows the school to purchase less chiller tonnage.  
 2  Smithfield Selma High School Johnston Smithfield Selma High uses 10 Calmac Ice Storage tanks to supplement its 155-ton and 215-ton Trane air-cooled Series R screw chillers that reduce the KW load during the peak electricity demand hours from 10 AM to 2PM. Without the ice system, cooling would require 488 tons of chillers, a difference of 153 KW. With the SGS-TOU rate from its electric supplier, Town of Smithfield, the facility saved $44,000 in 2002-03 on electric cost. There is little upfront cost for the system as compared to a conventional chiller unit, as the inclusion of ice storage in the system allows the school to purchase less chiller tonnage.  
 3  Cleveland Middle School, Johnston County Schools Johnston Cleveland Middle School uses 9 Calmac Ice Storage tanks to supplement its two 125-ton Trane air-cooled Series R screw chillers that reduce the KW load during the peak electricity demand hours from 10 AM to 2PM. Without the ice system, cooling would require two 200-ton chillers to condition the school. At $60,000 more in capital cost than a conventional chiller unit, the ice storage system offers a projected savings for Cleveland Middle of $26,000.00 per year. This would translate to a pay-back period of around 2.3 years for the difference in the purchased capital.  
 4  Wake County Social Services Building Wake The ice storage system for the Wake County Social Services Center is designed around a weekly load shifting concept. With this concept, the harvesters (ice makers) produce ice during off-peak hours on weeknights and weekends and do not operate at all during on-peak periods. Weekly load shifting takes advantage of extended weekend hours to downsize ice harvester equipment, thereby minimizing initial capital investment and decreasing the pay-back time. For the Social Services Center, the additional capital investment for ice storage with weekly load shifting is $215,000 compared to a conventional chilled water system. Estimated utility cost savings for the ice storage system is $50,000 per year, yielding a simple pay-back on investment of 4.3 years. Besides utility cost savings, the ice storage system offers several other advantages over a conventional cooling system. The ice storage system produces very low chilled water temperatures, which allows the Wake County Social Services Center to use a low temperature air distribution system. System advantages include smaller air handling units, smaller piping, smaller ductwork, and smaller building pumps as compared to a conventional air system.  
 5  East Clayton Elementary, Johnston County Schools Johnston East Clayton Elementary School uses 7 Calmac Ice Storage tanks to supplement its 110-ton Trane water-cooled Series R screw chillers that reduce the KW load during the peak electricity demand hours from 10 AM to 2PM. Without the ice system, cooling would require two 125-ton chillers to condition the school. The cost was a little more in capital cost than a conventional chiller unit, but the ice storage system offers a savings for East Clayton Elementary School of $13,454.00 per year. This would translate to a pay-back period of around 2 years for the difference in the purchased capital.  
 6  Cooper Elementary School, Johnston County Schools Johnston Cooper Elementary School uses 4 Calmac Ice Storage tanks to supplement its one 125-ton Trane air-cooled Series R screw chiller that reduce the KW load during the peak electricity demand hours from 10 AM to 2PM. Without the ice system, cooling would require two 125-ton chillers to condition the school. Ice Storage was less than a new chiller in capital cost, and the ice storage system offers a savings for Cooper Elementary School of about $7500.00 per year.  
 7  Riverwood Elementary School, Johnston County Schools Johnston Riverwood Elementary School uses 6 Calmac Ice Storage tanks to supplement its two 90-ton Trane air-cooled Series R screw chillers that reduce the KW load during the peak electricity demand hours from 10 AM to 2 PM. Without the ice system, cooling would require two 125-ton chillers to condition the school. At $80,000 more in capital cost than a conventional chiller unit, the ice storage system offers a projected savings for Riverwood Elementary School of $14,460 per year. This would translate to a pay-back period of around 5.5 years for the difference in the purchased capital.  
 
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