Oct. 1, 2011
by Charlotte Atchley
Freezing and cooling products hot from the oven takes energy — a lot of energy. During the past two or three years, Air Management Technologies, Inc., Lewisburg, PA, has adapted the thermal storage technology it uses in commercial buildings to the baking industry to help manage that energy use.
Air Management Technologies employs phase-change materials (PCMs) to cool commercial buildings. Facilities equipped with PCMs typically run air refrigeration systems at night when electricity rates are lower and then use the energy stored in the PCMs to cool the building during the day, thus saving on electricity costs. The same concept works in the bakery.
Scott Houtz, president, Air Management Technologies, described how PCMs function as an ice pack or battery. Typically, PCMs could be a plastic ball the size of a softball that contains a salt mixture. They sit in a tank, which is then flooded with water or glycol fluid. The PCMs absorb or release thermal energy based on their temperatures and the temperature of the fluid.
A bakery with intermittent refrigeration loads can store this cooling energy during nonpeak load times to be released during peak load times throughout production. This eases the burden on a plant’s freezing or cooling system and provides a more stable refrigeration load. PCMs also can be beneficial for plants that have undersized refrigeration equipment, according to Mr. Houtz
“Phase-change materials can be a lifesaver for those who have maxed out their refrigeration plant,” Mr. Houtz said. With the ability to use undersized equipment to store energy in PCMs, facilities can handle peak demand. In some cases, a bakery’s undersized equipment can handle 75% of its cooling needs with PCMs picking up the last 25%.