A Matter of Insulation: Acquisition vs. Lifetime Savings

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.

Insulation Strength Weakness
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.

Polyurethane & Extruded Polystyrene walk-in insulation
Polyurethane & Extruded Polystyrene

An energy saving experiment for your grocery store

A research study at Kettering University in Michigan investigated how to make an open refrigerated display case (like those found in grocery stores) operate more efficiently.  The study concluded that raising the temperature setting while lowering the air velocity from the refrigeration would not only provide energy savings, but the food was actually kept cooler.

Lower infiltration [of warm air] means the air is coming out at a lower velocity, said Navaz. “Previously, air came out of the upper vent (or grille) of a specific display case at 90 feet per minute. We calculated the optimal speed as 65 feet per minute as an optimal discharge air velocity to yield lower infiltration rate,” he said.

By reducing the velocity by 30 percent, infiltration was reduced by 12 percent and the power required was reduced by 13 percent.

Increasing the temperature at the discharge air grille by about 1 degree (F) and lowering the velocity of air resulted in lower suction pressure at the compressor inletwhich reduced the compressor usage and therefore less energy consumption.

Infiltration represents 83 percent of the cooling load and is the biggest draw on energy of refrigerated display cases. Less energy use translates into real cost savings to the tune of about $13 million for the state of California alone, according to Navaz.

In addition to energy savings, lowering the pressure on the compressor also extends the life of the compressor and creates more cost savings over the long term.

Click here to read the entire Kettering refrigeration study.

Energy Efficient Copeland Scroll Compressors for Walk-ins

compressor
Copeland Scroll Refrigeration Compressor

Save valuable resources with energy efficient Copeland Scroll compressors, permanent split capacitor motors and electronically commutated evaporator motors on your next refrigeration system purchase. Scroll condensing units are available for medium and low temperature refrigeration applications. The condensing units are optimized to work with HFC refrigerant R-404A, a reliable alternative to HCFC R-22. As the energy efficiency trend increases, the use of scroll compressors is a more important feature than ever before. Scroll compressors are inherently more reliable because they have significantly fewer moving parts and handle liquid slugs and debris more effectively. The scroll technology has only three moving parts, as compared to the standard hermetic compressors that have 150 plus moving parts. Scroll is effective in using less energy or amp draws verses the standard hermetic compressor. Copeland studies indicate that up to a 15% reduction in energy use is experienced for most applications. When adding the benefit of PSC motors on condensers and EC motors for evaporators, energy use will decrease. Sizing refrigeration equipment to operate for 14 to 16 hours instead of the traditional 16 to 18 hour run time will also save energy by using less kilowatts and costing less to operate compressors and motors.

Convenience Store Efficiency

The following article excerpt, Cooler Control, from the Convenience Store Decisions magazine, discusses ways to increase your walk-in cooler’s efficiency and decrease operating costs.

Convenience store chains can slash operating costs by as much as 10% with sound maintenance and general improvements to its refrigeration systems.

Operators looking for greater energy efficiency should cast an eye on their coolers, where centralized controls, lighting adjustments, basic ongoing maintenance and employee training can save them money.

“Coolers are typically an opportunity for improvements in maintenance and operational practices,” said Jerry Lawson, national manager for Energy Star Small Business and Congregations Network, a division of the U.S. Environmental Protection Agency in Washington. “With all the different types of equipment in the c-store, coolers are a key piece of the energy equation, and they are typically the most expensive to run. With the right improvements, there is an energy efficiency dollar saving opportunity.”

Where to begin? Start with the obvious.
“Keeping them clean is the biggest thing,” Lawson said. “Coolers have to breathe. Keeping those coils clean allows them to breathe; they take the air in and expel air out.”

When taking care of monthly cooler cleaning, Lawson liked to pull off the back panel and take a cloth or other type of non-steel brush to it and clean it off, then vacuum or sweep the junk up off the floor. “That’s the biggest thing to keep them running efficiently.”

Matt Lauck, director of marketing for Retail Solutions in Kennesaw, Ga., a subsidiary of Emerson Electric, said that central facility management systems can be a major tool for achieving energy efficiency in coolers. Such systems give the operator the ability to optimize energy reduction by, among other things, tracking temperatures to make sure they stay within operational norms, which obviously also has implications for food safety. “Think of it as a programmable thermostat,” he said.

Get a Small Business Grant to Help Purchase Your Walk-in Cooler or Freezer

government-grantsBeing “green” and “energy efficient” are big advertising buzzwords today.
But besides the benefits to the environment, there are definitely good economical reasons for “going green“. There is a HUGE potential for savings on your next electric bill. However, investing in new efficient equipment like walk-in freezers, furnaces, or stoves often present too much of an up front cost (even if they would pay for themselves in energy savings in a few years) so the purchase is delayed as long as possible. Think you can’t afford that new refrigerator or ice machine? Maybe you can with the help of your state government.

In this political environment there are many grants available for small businesses, especially when it comes to making your business more energy efficient. The following is a list of websites where you can find and apply for grants in your state (most are linked to the state’s business website but some are linked to specific energy grants). There is also an online government grant and loan search available. Different grants have different requirements and payouts (for example, some will require you to reduce energy usage by at least 20% and the state will foot 25% of the equipment bill).

Economic Development Websites:

Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming

Note: Website links accurate as of 8/22/2014. Let us know of any changes in state website links.

Walk-in Cooler & Freezer Shopping Tips

shopping walkin coolerBe aware when shopping for walk-ins online that you are comparing the same size box and refrigeration. Some companies are offering smaller sized refrigeration packages, which make it look cheaper upfront but may not provide you the results you are looking for.

Some systems, whether they are coolers or freezers, are designed only to hold the temperature of the product coming in and are not designed to pull-down the temperature of the product to the desired holding temperature. Pull-down happens when there is product entering the cooler or freezer that is warmer than the desired temperature and needs to cool in a short amount of time. For example, when a restaurant owner has a large pot of soup that needs to be cooled quickly to avoid bacteria growth, the refrigeration must be able to cool the soup to the desired temperature in a reasonable and safe time while maintaining the holding temperature in the cooler/freezer. Systems designed for holding only and not to pull down the temperature of the product coming in will only work properly if products entering the box are already at the desired temperature, either cold or already frozen.

The industry standard design temperature for freezers is at -10° F. Some online companies are selling their freezer refrigeration at a holding temperature of 0° F. If you try to run a walk-in designed for 0° F holding temperature and set the thermostat to -10° F, it will run constantly trying to meet the -10° F temperature it was not designed to hold. This will shorten the life of the compressor and may cause the coil to freeze and consequently warm up the box to melting temperature, damaging the food stored inside.

Before purchasing, you must understand the difference and what implications it could have on your business. Most perishable items that are stored in a freezer are not frozen to start with and will need to freeze and stay frozen for a period of time. If the box is designed for holding temperature only and is set at 0° F, the refrigeration will work harder and longer to pull the temperature inside the box back down to 0° F once warm food is stored in the freezer. Frozen products, such as ice cream, hold up better at -10° F rather than 0° F. When a freezer goes into defrost it can raise the box temperature by 10-15°. If your box is set at 0° F, a 10-15° temperature swing can cause some products to be damaged or melted. When dealing with food it is imperative to make sure the holding temperature in the freezer is low enough to keep products frozen, protecting from bacteria or other hazards that spread through food not refrigerated correctly. (Check with your local health codes for the required holding temperature of your walk-in cooler and freezer.) It is also important to note that when refrigeration is working longer and harder, your energy costs will increase as well as the chances of your refrigeration breaking down or having inefficiencies.

Every state has requirements for storing cold food; here is an example of Illinois’s Administrative Code.

U.S. Cooler Saves Customers Money with Energy Efficient Walk-ins

stacked walk-in panels
Extruded polystyrene panels for walk-ins.
Most walk-in coolers and freezers are purchased based upon the initial cost. What many fail to realize is that operational costs can dig deep into consumers’ pockets. U.S. Cooler is giving the Cold Storage Industry an energy efficient option by manufacturing walk-ins with extruded polystyrene insulation.

Extruded polystyrene is the most efficient insulation available on the market. Over time, extruded polystyrene resists moisture while other insulations start absorbing it. One must consider a real life application to understand moisture absorption.

Freezers normally operate at -10° F inside, but may have an exterior temperature of up to 95° F or even more. With the extreme difference in temperatures, the insulation is vulnerable to retaining moisture in the structural voids. When water starts collecting inside walk-in insulation, the R-value drops and moisture inside the insulation starts to freeze.

r-retentions1

When moisture is absorbed and R-values start to decrease, refrigeration systems start working harder and longer to make up for the heat transferring into the walk-in. A refrigeration system working overtime means higher energy bills. By using extruded polystyrene, consumers can save that money.

Extruded polystyrene is unique; the insulation is a closed-cell product, meaning the cells of the material are so tightly packed together that moisture has a difficult time penetrating, which is optimal for moisture resistance and keeps the R-value from decreasing.

Using studies performed by the U.S. Army Corps of Engineers (CREEL), U.S. Cooler demonstrated extruded polystyrene saved consumers over $5,000 in energy costs over the first five years of operation. The savings again are due to extruded polystyrene’s ability to resist moisture and to retain its R-value better than other insulators.

energy-savings2

When buying and selling walk-ins, consider more than the initial cost of the walk-in-consider energy costs. Educate yourself about how to save money; to find out more about extruded polystyrene and energy savings, call 800.521.2665 or visit www.uscooler.com.

U.S. Cooler at the 2009 National Restaurant Association Show

nra

U.S. Cooler exhibited at the NRA Show in Chicago, May 16-19, 2009.

Since last NRA, U.S. Cooler has been busy working on new and innovative processes to reduce waste, inventory, time, and costs while increasing productivity. All of these factors together equal savings for dealers and consumers. Providing customers with quality, affordable walk-ins in a convenient amount of time has always been U.S. Cooler’s highest priority.

U.S. Cooler, through their discount dealer program, passes savings on to consumers via the internet. Quick delivery, quality product, and competitive prices have drawn customers from across the nation to buy walk-in coolers and freezers from U.S. Cooler’s internet dealers online. Recently, prices were discounted even further, saving consumers even more money. Check out www.fastcooler.com, the internet’s best resource for discount walk-in cooler and freezer dealers.

Stop by U.S. Cooler booth 1834 to learn more about our discount internet program and how U.S. Cooler can save you money.