Your cold storage equipment may be one of the most important choices you make. A significant amount of costs are associated with your walk-in. Before you purchase, make sure you consider the entire lifecycle of the walk-in instead of just the acquisition price.
The two main elements that effect energy and cost savings while running a walk-in are the refrigeration and insulation. To get the optimal results from your refrigeration it must be sized correctly taking in consideration the size of box, if it is a cooler or freezer, and what will be stored inside. (There are many other factors that are considered when sizing refrigeration.) Insulation is the key to energy savings because it is responsible for holding the cool temperature in the box so the refrigeration does not have to work overtime. Insulation quality is measured by R-value; the resistance to heat flow through an object. Since EISA was implemented January 1, 2009, all walk-in manufactures are required to have an R-value of R-25 for coolers and R-32 for freezers. Now that all manufacturers follow the same requirements, the performance of the insulation is what differentiates the walk-in.
The two common types of insulation used are polyurethane and extruded polystyrene. Each type of insulation brings with it strengths and weaknesses that must be evaluated for each individual application.
|Extruded Polystyrene||Starts with a high R-value. Smaller cell structure. Resists moisture absorption. Closed cell structure.||Out gases some. Over time, R-value decreases minimally.|
|Polyurethane||Starts with a high R-value. Closed cell structure.||Out gases more. Over time, R-value decreases steadily. Is susceptible to moisture infiltration.|
U.S. Cooler uses both insulations. Through experience and research, U.S. Cooler believes extruded polystyrene is the best insulation for the walls, ceiling, and floors of coolers and freezers. Polyurethane is better to insulate the doors of their walk-ins. According to a study performed by the U.S. Corps of Engineers, they found that over a five year period extruded polystyrene retains 75% of its R-value while polyurethane retains 25%.¹ This is one reason why U.S. Cooler believes extruded polystyrene provides the most value and the best option for walk-in insulation.