Icemakers are Getting Greener

Icemakers are Getting Greener

These valued machines haven't been ignored in the quest for increased efficiency in the HVACR world. Improved designs and proper maintenance procedures by technicians are helping end-users save energy.

To operate greener is to use less of our natural resources — renewable or non-renewable — to produce more products and services that affect our daily lives. It can apply to the products and services we use, to our factories and jobs, our homes, and our transportation. In case I forgot something, it can basically apply to just about everything.

In the air conditioning and refrigeration world, it applies to using less energy to cool our products and ourselves. Specifically, in the icemaker industry, it includes the materials and manufacturing processes, the component parts, product design and packaging. For the sake of discussion in this article, we'll focus on the final product. From the product standpoint, being green means to use less energy and water to produce and harvest ice for various commercial uses and for food consumption. We can all agree that using less energy and water is good for our environment. And, considering the cost of these resources; it's good for our wallets.

Standards Have Been Established

In the push towards greener living, many groups who are concerned with our environment have come together to promote better efficiencies in products and services. The California Energy Commission (CEC) was created in 2004. Where icemakers are concerned, the commission pushed for a reduction in electrical and water consumption in icemaker operation, to use fewer recourses to produce more ice. The CEC established specific efficiency standards and ratings for these products to make them more energy efficient. CEC compliance was made mandatory for icemaker products produced and sold in California beginning in January, 2008. The Federal government's Department of Energy (DOE) has adopted these standards and ratings, and passed legislation to make them mandatory on all icemaker products produced and sold nationwide after January 2010. Other agencies like Energy Star® — a joint program with the DOE and U.S. Environmental Protection Agency (EPA) — have also created ratings for appliance products including some icemakers. These ratings promote better energy efficiencies and less cost to consumers. Some states are allowing rebates if the icemaker meets CEC or Energy Star rating criteria.

Improved Designs Build in Efficiency

Icemaker efficiency starts with the system design. Ice machine companies have been working diligently in the last few years to design products that are more efficient, and that meet CEC and DOE compliance. At the same time, they try to meet Energy Star goals, so that they can carry the nationally-recognized Energy Star logo.

An ice machine has a basic refrigeration system with hot gas defrost components to harvest the ice and a water supply and circulation system. Like every refrigeration system, an icemaker has an evaporator “freezing surface,” a compressor, a metering device, and a condenser. These are the basic components necessary for a refrigeration system. In addition, a hot gas valve and harvest controls are added to the basic refrigeration components to release the ice from the freezing surface.

A Balanced System

The first concern in an efficient design is to assure that the basic refrigeration components are balanced properly. This, along with the optimum refrigerant type and charge, will provide the efficient operation and production of the icemaker. Adequate hot gas is required to heat the evaporator during harvest to release the ice with minimum meltage. To accomplish this, proper compressor discharge temperatures and hot gas valve sizing and distribution are important factors. Typically, the current refrigerant of choice for icemakers is either R-134A or R-404A. Either of these HFC blends can be used, but the most common would be R-404A. Icemaker design engineers are constantly looking for new more efficient refrigerants and component combinations so the refrigerant of choice may change in the future.

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The one constant in icemakers is the need for water. In the cuber ice making process, pure water freezes and minerals are washed out. As a result, at the end of the cycle, the reservoir contains a high concentration of these minerals. Over time the minerals leave deposits on the evaporator plate and in the water distribution system in the form of scale. Scale impedes heat transfer and reduces efficiency. An icemaker will usually have a short purge cycle to remove these minerals however this does use additional water. Engineers have worked diligently to find ways to reduce water consumption and still maintain a clean icemaker.

Keeping it Green

Proper installation is essential for proper and efficient operation. Consult the instruction or installation manual first. It contains the manufacturer's installation tips and recommendations. The installer should always follow the manufacturer's installation recommendations. The unit should be located in an area with decent ambient conditions and adequate clearances for service and maintenance. This will help to assure efficiency along with the installation of adequate water treatment to improve the local supply water quality. Properly sized water and drain lines are also important. A commercial ice maker always requires a separate power supply circuit that is properly sized. Installing an ice maker on a circuit with other loads will affect the compressor startup, which would reduce efficiency, and could also shorten the component life.

Preventive Maintenance Supports Efficiency

To maintain efficiency, regular preventative maintenance is required. A cleaning and maintenance label is usually included in a conspicuous place on the unit. The instruction manual will include cleaning instruction and recommendations.

Scale is the enemy of the ice maker. Once it builds up on the evaporator and in the distribution system, it will reduce the production and efficiency of the unit. When a scale film covers the freezing surface, it insulates, impedes heat transfer and affects ice production and harvest. This scale film must be removed. An acid based cleaner is required to effectively loosen and remove the scale.

Some machine parts may need to be removed, inspected and cleaned separately. Once the unit is cleaned, it should also be sanitized. Sanitizing reduces bacteria that can grow in the cold dark environment of the ice maker. Remember that ice is a food product, and the ice maker must be cleaned and sanitized.

For a green ice machine, follow the path from the design and installation through preventative maintenance. It will lead you to an icemaker that's good for our environment.

Danny Moore is Director of Technical Support for Hoshizaki America, Inc., a manufacturer of commercial ice equipment and reach in refrigeration. See website at www.hoshizakiamerica.com.

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