20-30% energy savings with hydrocarbon ice machines

By Janet Thompson, May 07, 2013, 12:24 2 minute reading

For the development of an energy efficient and environmentally friendly ice machine, Manitowoc Ice, Inc. teamed up with Danfoss. Together, the companies created two new models within Manitowoc’s Indigo Series and two Q-series under-counter units, all cooled with hydrocarbons. One study showed 20-30% less energy consumption in the R290 ice machine than in comparable systems.

To improve energy efficiency of its products and to support customers’ sustainability efforts, Wisconsin-based commercial ice machine specialist Manitowoc Ice, Inc. turned to Danfoss, a leader in the research, development and production of low GWP refrigerant products, to help implement its ideas. By using the natural refrigerant R290, the two companies were able to develop ice machines using a non-ozone depleting and low global warming potential refrigerant, which also improved energy efficiency and reduced operating costs.

Currently, these innovative ice machines are available for the European market. They will have to overcome several hurdles before the SNAP approval process is able to begin and they can be approved for the US market.

About the system

The first collaborative project was the conversion of Manitowoc’s 500-pound ice machine to natural refrigerants, for which Danfoss replaced the original R-404a compressor with one of its SC Series compressors (SC18CNX) for hydrocarbons. In addition to reducing energy consumption, this compressor featured a compact and reliable design, as well as a motor with specially optimised valves and internal motor protection. The SC compressor also offered high cooling capacities, low noise levels and low energy consumption at high ambient temperatures.

The energy efficiency of the ice machine was further improved by Manitowoc’s use of a specially designed Danfoss TU thermostatic expansion valve, which optimised the charge and regulated the injection of the refrigerant. Finally, the original condenser was replaced with a new Danfoss microchannel condenser.


The overall ice production capacity of the system was maintained while staying within the 150g-charge limit, despite the switch in refrigerants. This was achieved through increased compressor displacement with R290, reduced operating pressure within the microchannel heat exchangers and optimised component selection. Moreover, the system saw a 20-30% energy savings when compared to other ice machines, due to the lower pressure ratio and discharge temperatures of R290, as well as the high efficiency of the compressor and components.

About Danfoss

The Danish company Danfoss is a global leader in the research, development and production of high efficiency electronic and mechanical components and controls for air-conditioning, heating, refrigeration and motion control systems. With a strong commitment to environmental responsibility, Danfoss continues to lead the industry in the adoption of natural refrigerant solutions.

About Manitowoc Ice, Inc.

Since 1964, Manitowoc Ice, Inc. has specialised in the building of ice machines. At its Wisconsin facility, the company designs, manufactures and markets a complete ice machine product line with 200+ models with capacities ranging from 30 to 1,536 kg of ice per day.


By Janet Thompson

May 07, 2013, 12:24

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