The Natural Refrigeration Review is a quarterly publication that contains technical articles, regulatory and code updates, industry news and information about IIAR activities and publications. It is distributed by email to all IIAR Members and IIAR Contact lists.
SUMMER 2026 THE NATURAL REFRIGERATION REVIEW
The Natural Refrigeration Review issues are available as PDF downloads for both lIAR members and non-members, or as individual article posts below. Click the button to view the full issue, or scroll through all the individual issue articles below.
2025 Tech Paper: CO2 Heat Pumps: System Solutions and Applications Mapping
CO2 is an emerging refrigerant in North America, but identifying its suitable applications can still be challenging. In Europe, CO2 has been used in heat pumps for several years. This paper discusses the experience of using CO2 in heat pumps in Europe, giving the basics of its use as a refrigeran...
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2025 Tech Paper: Livin’ la Vida LOPA: A Case Study in the Application of HAZOP and LOPA for Ammonia Refrigeration Systems
Since the advent of process safety, the process hazard analysis (PHA) method of choice across the refrigeration industry has been the what-if/checklist technique. Over the last 20 years, many companies’ and industries’ hazard assessment methods have matured. While the hazard and operability (HAZO...
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2025 Tech Paper: Connecting Cooling and Process Heating in Industrial Applications with Natural Refrigerants
The need to decarbonize industrial facilities is greater than ever. One technology that will play a large role in reducing carbon emissions is industrial heat pumps. With hundreds of different combinations of industrial heat pump systems, engineers and designers need to understand which technolog...
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2024 Tech Paper: Application of a Rotary Pressure Exchanger in CO2 Refrigeration Systems
Herein, the application of a rotary gas pressure exchanger (PX) for increasing the efficiency of transcritical CO2 refrigeration systems is examined. The PX uses high-pressure discharge from a condenser/gas cooler as a motive fluid to compress the low-pressure flash gas with minimal external ener...
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2024 Tech Paper: CO2 Systems Add-Ons: Calculations and Field Measurements
This paper describes enhanced and integrated carbon dioxide refrigeration systems that can improve yearly energy figures when compared to traditional flash-gas bypass (FGB) solutions, making CO2 an attractive option for industrial refrigeration in some regions.
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2025 Tech Paper: Getting Knocked Out by the Pendulum: The 2024 EPA RMP Rule Changes and Strategies for Compliance
Over the last several years, facilities covered by the Environmental Protection Agency’s Chemical Accident Prevention Provisions, otherwise known as the Risk Management Program, have beenforced to navigate unpredictable and frequent shifts in policy. This paper is intended to familiarize readers ...
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2024 Tech Paper: Energy Savings in Ammonia Systems Using Low-Stage De-superheating
This paper demonstrates how evaporative condensers can be used as low-stage de-superheaters to improve the efficiency of two-stage ammonia refrigeration systems. The high discharge temperatures generated by ammonia compressors can help reject heat to ambient heat sinks, thereby reducing the load ...
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2024 Tech Paper: Energy Baselining Essentials
Before companies can report on progress toward sustainability goals, they need to establish a baseline. This paper outlines fundamental best practices for creating a useful energy baseline: defining the metrics upfront, normalizing the data, setting up real-time monitoring, and submetering specif...
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2024 Tech Paper: Cues and Confirmation Your Piping is in Jeopardy: A Comparison of 20+ Years of NDT Dat with Field Observations
Ammonia refrigeration system managers are looking for more useful information regarding risk mitigation and compliance because they need to determine whether components are fit for service or vulnerable to damage, and when to act. Insulated piping is subject to corrosion under insulation (CUI), b...
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2024 Tech Paper: Implications of HAZWOPER Regulations on Ammonia Refrigeration Contractors
This technical paper addresses potential business risks associated with the Hazardous Waste Operations and Emergency Response (HAZWOPER) standard for ammonia refrigeration contractors when used for repairing leaks in ammonia refrigeration systems. The definitions of an incidental leak and leaks r...
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2024 Tech Paper: Application and Considerations for Internal Relief in Industrial Refrigeration Systems
The requirements for determining the capacity of vapor service pressure-relief devices applied to partially liquid-filled ammonia vessels/equipment and discharging to the atmosphere, as well as liquid service relief devices completely filled with non-volatile liquid (e.g., compressor oil) dischar...
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2024 Tech Paper: Controlling the Circulation Rate in Ammonia Refrigeration Systems
Reducing the charge in ammonia refrigeration systems is becoming increasingly important. However, reduction must be achieved without compromising the efficiency of the ammonia refrigeration system.
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2024 Tech Paper: Intelligent CO2 Compressors and Ejectors for Enhanced System Efficiency and Reliability in Industrial Applications
Intelligent CO2 compressors and ejectors are emerging as highly promising solutions for industrial refrigeration systems. This publication highlights their expanding capacity and scale, demonstrating their suitability for various applications, including cold storage facilities, distribution cente...
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2024 Tech Paper: Falling Film Chiller and Heat Pump Integration: An Energy-efficient Method for Producing Cold and Hot Water in a Dairy Plant
Decarbonization is a crucial process in the effort to mitigate the effects of climate change. Considering this aim, efficient energy utilization is also imperative for sustainable and cost-effective operations in dairy plants. In general, the refrigeration system rejects heat to the atmosphere on...
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2024 Tech Paper: Carrots to Sticks – Carbon Tracking for Cold Storage
This paper provides an overview on the basics of carbon counting and how they may apply to carbon counting within the cold storage industry. It will also cover opportunities to take advantage of newer technologies available to improve the accuracy of carbon reporting data, and the ability to gene...
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2024 Tech Paper: Correlation Between Evaporator Suction Pipe Size and Hot Gas Flow Rate for the Prevention of Hydraulic Shock in Ammonia Refrigeration Systems
Chidambaram Narayanan, External Consultant Joel-Steven Singh, Senior Engineer AFRY Switzerland AG
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2023 Tech Paper: Cybersecurity in Automated Industrial Systems
The rise of automation brings new cybersecurity threats to heavy industries. Cybersecurity attacks like ransomware, malware, and phishing are becoming commonplace and more sophisticated as they continuously evolve and change. This paper reviews the risks and tactics of the most common classes of ...
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2023 Tech Paper: Performance Analysis of CO2 Heat Pump Modes for Refrigeration Systems: A Case Study
Transcritical CO2 heat pumps are emerging as a viable alternative to synthetic air- or water-source heat pumps, and they present an opportunity for electrification while eliminating the need for refrigerants with high global warming potential. The purpose of this technical paper is to assess the ...
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2023 Tech Paper: The Cost of Non-Compliance: An Objective Analysis of Federal EPA’s Enforcement at Ammonia Refrigeration Facilities
This paper presents an objective analysis of the Federal Environmental Protection Agency’s (EPA’s) enforcement of ammonia refrigeration facilities across America conducted using hundreds of publicly available independent inspection reports dating from 2006 through 2021...
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2023 Tech Paper: Carbon-Dioxide System Relief Sizing
Generally, safety standards for refrigeration systems require the placement of at least one overpressureprotection device on all carbon-dioxide (R-744) systems as well as on vessels manufactured in accordance with the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Secti...
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