1

EPA SNAP Submittal – Revision to Extend R-290 Use to Commercial Ice Machines

Manitowoc Ice, Inc.

D. Erbs - 9/9/13 and D. Walker 10/9/15

Summary

Manitowoc Ice is strongly committed to continuous improvement in the sustainability 

and environmental impact of the products that it produces. We have been a leader in our 

industry segment in advances to the energy efficiency of our products, advocating and 

supporting the creation of an EnergySTAR category for commercial ice machines, and an 

early adopter of alternate substances for both refrigerants and blowing agents for foam.

As a result of our development and introduction of R-290 commercial ice machines into 

the EU market, we have arrived at several realizations: 1) R-290 can be safely used in 

commercial ice machines that have a factory sealed refrigeration system with relatively 

minor modifications, 2) 150 g of R-290 is sufficient for a commercial ice machine with 

500 lbs/day of ice production, and 3) energy efficiency is significantly improved when 

compared to HFC-404A. The opportunity to extend these benefits to the product that we 

produce and sell in the US is the reason for this submittal to EPA.

Submission

Extend the SNAP listing for R-290 to find acceptable, subject to use conditions, as a 

substitute for CFC-12, HCFC-22, and R-502 in commercial ice machines with a factory 

sealed refrigeration system and charge of 150 g or less for each sealed refrigeration 

circuit.

Supporting Information

1. Ice Machine Overview: Commercial ice machines generally employ a vapor 

compression refrigeration cycle to provide the necessary refrigerating effect to 

cause liquid water to freeze into ice. Figure 1 is a schematic for the basic 

components and refrigeration system circuit.
2

Figure 1 – Ice Machine Refrigeration Schematic (Freezing Cycle)

Figure 2 indicates the refrigerant flow and states during the harvest cycle, where hot gas 

flows directly from the discharge of the compressor to the evaporator inlet, bypassing the 

expansion valve, and causing the evaporator to warm and release the ice from the 

evaporator.

Figure 2 – Ice Machine Refrigeration Schematic (Harvest Cycle)

The condenser coil contains the largest percentage of the total charge in the ice machine, 

followed by the evaporator, the refrigerant line between the condenser outlet and 

expansion valve inlet, and the suction line between the evaporator and compressor. 

During harvest, the evaporator charge amount will increase due to the condensation of 
3

refrigerant that occurs when higher pressure refrigerant enters the evaporator from the 

compressor discharge line. The receiver shown for water cooled designs is required to 

balance refrigerant charge during off design operation due to the limited internal volume 

in the water cooled condenser.

All refrigeration piping and components are contained within the cabinet and can only be 

accessed by removal of the exterior panels through the use of tools. Warning labels are 

placed on the exterior of the unit and at various interior locations to indicate the use of R290 as the refrigerant and the associated flammability hazard.

System designs illustrated are identical in component type and function to those 

employed in retail food refrigerators or freezers with hot gas defrost. These systems were 

approved for use under SNAP regulation final rule 17 effective February 21, 2012.

2. Safety Regulations and Risk Assessment

For the US market, the relevant UL safety standard for commercial ice machines is UL 

563. UL completed the supplement SA to UL 563 in November 2013, which covers the 

use of a flammable refrigerant in commercial ice machines:

SA1 Scope

SA1.1 The requirements cover ice makers that employ a refrigerant that has been 

identified as having flammable characteristics.

SA1.2 The requirements in this supplement are in addition to the applicable requirements 

in the Standard for Ice Makers, UL 563.

Supplement SA to UL 563 follows essentially the same requirements for construction, 

labeling, and testing for commercial ice machines that were developed for commercial 

refrigerators and freezers in UL 471. UL 563 forms a significant basis for use conditions 

required to find R-290 acceptable for commercial ice machines.

Manitowoc Ice also notes the risk screen for use of R-290 in small commercial 

refrigeration systems (ICF, 2009b and ICF, 2011b) cited in the final rule for docket EPAHQ-OAR-2009-0286 which found the risk to be acceptable. Commercial ice machines 

are generally located in kitchen or other areas that are restricted to general public access, 

employees working in these areas are trained on the safe use of equipment in the kitchen 

area, and the size and ventilation required for a typical commercial kitchen does not 

allow for situations where a charge release of 150 g of R-290 can result in a significant 

concentration build up in the indoor air surrounding the ice machine. Based on our 

analysis of the relative risk factors for a commercial freezer in a retail food store

compared to an ice machine in a commercial kitchen, the risk associated with a 

commercial ice machine does not exceed that of a commercial freezer in a retail or 

commercial setting.

Manitowoc Ice has detailed field service records on refrigerant leakage incident rates for 

its ice machines. Analysis of the records for factory sealed refrigeration systems (“ice 

making heads”) is attached to this submission. It should be noted that the data include 

leaks that occur from the service access valves that are provided on the R-404A units, and 
4

these valves have been removed from the R-290 systems, further reducing the expected 

leakage rate for R-290. Most leaks are small pinholes that occur at braze joints, further

minimizing the risk in the event of a leak.

3. Service Training

Manitowoc offers a 5 year parts and 3 year parts and labor warranty on the sealed 

refrigeration systems in its ice machines. Before a service company is eligible to 

complete service work that is covered by warranty, they must complete a Manitowoc Ice 

service training course and become certified for each class of equipment. Manitowoc has 

developed a special training course to cover service of ice machines that use R-290 

refrigerant, and before any service company can work on the R-290 ice machines, they 

must complete this training and obtained the necessary equipment. A copy of a service 

training presentation on R-290 is attached to this submission.

• Energy Efficiency

The range of improvement in energy efficiency varies due to several factors:

 The difference in compressor EER between the R-404A model and the R-290 

model

 The change from a conventional round tube-plate fin condenser coil to a microchannel condenser to reduce charge amount for R-290

Figure 4 is a theoretical comparison between R-404A and R-290:

Figure 4 Theoretical COP Comparison of R-290 with HFC Refrigerants

At the evaporating temperature typically found in an ice machine application, the 

theoretical advantage of R-290 over R-404A is a 20% improvement in efficiency.
5

Manitowoc has also completed performance comparisons for lower GWP refrigerant

blends that have been developed as potential substitutes for R-404A as part of the AHRI 

Low-GWP AREP program. The performance comparison is shown in Figure 5:

Figure 5 Performance of Low GWP Refrigerant Blends in Commercial Ice Machine

N-40b (R-448a) has a GWP of 1331 and has been classified as A1, while L-40 has a 

GWP of 285 and is classified as A2L.

While L-40 and N-40b improved the efficiency, the gains were in the range of 1 to 3%, 

significantly below the gains measured for R-290.

4. Exposure Concentrations

Typical room sizes where commercial ice machines are used would be 50 square meters

and a minimum room size of 9 square meters.

Workplace exposure concentrations have been evaluated and deemed safe in Reference 

Docket ID No. EPA-HQ-OAR-2009-0286 for commercial refrigeration. Use in 

commercial ice machines poses same risks and therefore should be deemed safe for this 

application.

[Data source: AHRI Low-GWP AREP Report 002, 2012]
6

5. Flammability Risk Assessment

Manitowoc has completed a full quantitative fault tree analysis as well as a design failure 

mode effect analysis (DFMEA) for the use of R290 in commercial ice machines. The 

high level fault tree analysis structure is shown below. The detailed analysis is attached 

that reflects an extremely low risk for accident from fire/explosion in the specific 

application.