FiberLok Inc., located in Fort Collins, Colo., produces Lextra® Fiber Graphics such as heat transfers, appliqués (patches), stickers, and mouse pads. To manufacture a consistent product, the processing area must be kept at 62°F with 65 percent relative humidity (rh) and 100 percent make-up air. Initially the area was cooled with 24 tons of conventional cooling equipment, but when outside air temperatures approached more than 95° the process area temperature would exceed tolerance. This resulted in lost production time of as much as two weeks during the summer - FiberLok’s busiest time of year.

In an effort to combat the problem, the company installed two Ice Bear® systems and cooling coils in existing ductwork downstream of the conventional air conditioning system. The Ice Bear units are used as the first stage of cooling. As outdoor air temperature rises, the conventional cooling will stage in as needed. Ice Bear is an energy storage technology that was developed as part of the U.S. Department of Energy’s (DOE’s) Inventions and Innovation program by Powell Energy Products and commercialized by Ice Energy®.

The technology works by shifting a/c energy use from peak to off-peak periods and storing the energy as ice. During peak daytime cooling, the unit functions as a condenser to provide cooling using a 300-Watt refrigerant pump to circulate ice-condensed refrigerant to the evaporator coil.

According to Ice Energy, benefits of the Ice Bear technology include:

• Shifts up to 95 percent of a/c load from peak to off-peak periods, saving energy consumption and lowering utility bills.

• Reduces energy requirements by 5 to 25 percent, depending on climate zone and application.

• Reduces air emissions from 23 to 40 percent.

Since the Ice Bear systems were installed at FiberLok, the company has successfully shifted 10 tons of cooling while increasing productivity. The Ice Bear unit is compatible with new or existing air conditioning equipment and can be used with rooftop and split systems from 3 to 10 tons. It offers energy storage capacity of 30 ton-hours at a load of up 5 tons.

Sidebar: Thermal Energy Storage

Ice Energy’s Ice Bear is an ice storage air conditioning module engineered to convert existing air conditioning equipment into thermal energy storage (TES) systems.

The Ice Bear is designed to meet retrofit, replacement, and new construction requirements in light commercial air conditioning and industrial process cooling. The unit can also be applied to larger homes and a wider range of residential applications is planned. The Ice Bear can be used to expand an air conditioner’s capacity, or perform two different energy conservation functions: load-shifting and load-leveling. Load-shifting provides the greatest demand reduction. Load-leveling, sometimes called partial storage, typically provides 40 percent demand reduction during peak cooling periods and up to 90 percent during months with small cooling loads.

The Ice Bear consists of a heat exchanger made of helical copper coils placed inside an insulated polyethylene storage tank, an air pump to enhance the heat exchanger’s heat transfer rate, a refrigerant pump, and an air-cooled condensing unit. To provide air conditioning, the Ice Bear pumps refrigerant to an evaporator coil in an air handler. By using the condensing unit to produce ice during the night and the refrigerant pump to supply condensed liquid refrigerant to the evaporator coil during the day, the Ice Bear may be used effectively to transfer the majority of load requirements to nighttime hours or to level energy loads.

For more information, visit www.ice-energy.com.

Publication date: 08/25/2008