SACRAMENTO, Calif. - The California Energy Commission has approved the Ice Bearâ„¢ 50 module, an ice-storage air conditioner, as an optional compliance measure for the latest revision of California's Title 24 building energy efficiency standards.

California's 2005 revision to the Title 24 building energy efficiency code considers the economic cost and societal impact of delivering electricity to California's 16 diverse climate zones every hour throughout the year. Historically, the standards viewed energy costs as flat over time and did not factor in the cost variances of providing energy to different areas of the state. The 2005 standards incorporate a new methodology referred to as the time dependent valuation of energy - or TDV. "We thoroughly evaluated the Ice Bear's potential as a compliance option and found it to be extremely effective in reducing on-peak air conditioning energy demand," said Charles Eley of Architectural Engineering Corp. (AEC). "It is very effective in reducing TDV energy, the CEC's new metric for measuring energy efficiency."

TDV methodology recognizes that energy used during a peak hour, for example on a scorching mid-August day, is valued up to 10 times more than energy consumed during low-cost, off-peak hours, such as 4 a.m. on a spring morning. Energy-consuming products are given TDV credits that rate their time-based energy efficiency and products that use less power during peak summer hours are rewarded with more TDV credits.

Conventional air conditioning units don't fare as well under TDV because they consume the same amount of energy during peak hours as during off-peak hours. In contrast, the Ice Bear product earns high levels of compliance credit, since it uses only 300 watts of peak energy while delivering a constant 7.5 tons of cooling capacity for about six hours.

The Ice Bear module attaches to conventional rooftop and split-system air conditioners that cool the majority of all light commercial and residential buildings. The module operates a standard condensing unit at night, when TDV energy is at its lowest, to freeze water in the Ice Bear module's insulated tank. Overall efficiency is maintained and operating costs lowered since nighttime temperatures are cooler and electricity less expensive.

The next day, when the thermostat calls for cooling, standard refrigerant - cooled by the ice - is pumped from the Ice Bear module to the existing cooling coil used in the building's air conditioning system, effectively replacing the conventional system's condensing unit during peak cost and TDV periods.

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Publication date: 06/05/2006