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Our goal is to be the leader in sustainable refrigeration and living up to our name we want to do ZERO harm to the environment and use refrigerants with ZERO ozone depletion.

First Things First

What does sustainability mean in the context of refrigeration? Let's dissect the key terms commonly used in refrigeration to discuss sustainability and identify important considerations.

Ozone Depletion Potential

ODP is a measure of the potential for a substance to deplete the ozone layer in the Earth’s stratosphere. The ozone layer plays a crucial role in protecting life on Earth by absorbing the majority of the sun’s harmful ultraviolet (UV) radiation.

Certain chemicals, particularly chlorofluorocarbons (CFCs) and some hydrochlorofluorocarbons (HCFCs), were found to contribute to the depletion of the ozone layer. As a result, international agreements, such as the Montreal Protocol, were established to phase out the production and use of ozone-depleting substances.

Refrigerants with a high ODP were replaced with alternatives that have either zero ODP or very low ODP, contributing to the protection and recovery of the ozone layer. Ammonia, hydrocarbons, and certain hydrofluorocarbons (HFCs) are examples of refrigerants with zero ODP.


Global Warming Potential

GWP is a measure of how much heat a greenhouse gas traps in the atmosphere over a specific time period, usually 100 years, compared to carbon dioxide (CO2). It is expressed as a numerical value, and the higher the GWP, the more warming potential a substance has.

Refrigerants are classified based on their GWP, and this classification is important in the context of climate change. High-GWP refrigerants contribute more to global warming over time, while low-GWP or zero-GWP refrigerants have a lesser impact.

The use of GWP is particularly relevant in the transition away from high-GWP refrigerants, such as hydrochlorofluorocarbons (HCFCs) and certain hydrofluorocarbons (HFCs), toward more environmentally friendly alternatives with lower or zero GWP. This transition is part of efforts to mitigate climate change and reduce the environmental impact of refrigeration and air conditioning systems.

Waste Heat Recovery

Heat reclamation, also known as waste heat recovery, is a sustainable practice in refrigeration that involves capturing and reusing the heat generated during the cooling process. Instead of allowing this heat to dissipate into the environment, it is harnessed for beneficial purposes, contributing to increased overall system efficiency and reducing energy consumption. Heat reclamation improves the energy efficiency of refrigeration systems by utilizing the otherwise wasted heat for additional purposes. One common application of heat reclamation is using the recovered heat for space heating in the same facility or building. This is particularly effective in colder climates where there is a simultaneous demand for cooling and heating.

By incorporating heat reclamation practices, businesses can experience economic benefits through reduced energy costs and increased operational efficiency. Simultaneously, the environmental impact is minimized as the overall energy demand and greenhouse gas emissions associated with heating are lowered.

Ammonia (NH3) is considered an environmentally friendly refrigerant for several reasons. It has zero ozone depletion potential (ODP), meaning it does not contribute to the depletion of the ozone layer. Additionally, ammonia has a very low global warming potential (GWP), making it one of the most environmentally benign refrigerants in terms of its impact on climate change. While ammonia is considered a green alternative, it’s important to note that it is not without challenges. Ammonia is toxic and flammable, so proper handling and safety measures are crucial in its use. It is commonly used in industrial refrigeration systems, food processing facilities, and certain commercial applications where its properties can be managed safely.

Carbon Dioxide

R-744 in refrigeration, has emerged as a sustainable refrigerant choice, reflecting a commitment to environmental responsibility. Notably, CO2 possesses a Global Warming Potential (GWP) of 1, which is significantly lower than that of many traditional synthetic refrigerants. This characteristic aligns with the overarching goal of mitigating climate change. Leveraging CO2 as a refrigerant is further underscored by its status as a natural and abundant substance in the Earth’s atmosphere, contributing to the adoption of eco-friendly refrigeration solutions.

Importantly, CO2 is non-ozone depleting, ensuring its environmental compatibility and positive impact. In practical applications, CO2 refrigeration systems, especially in commercial settings like supermarkets, have demonstrated energy efficiency. While CO2 is generally considered safe, it operates under high pressure, necessitating adherence to stringent safety measures and system design considerations for sustainable and secure operation. The incorporation of CO2 as a refrigerant reflects a broader industry trend towards embracing sustainable alternatives, marking a positive step in reducing the environmental footprint of refrigeration practices.


Propane (R-290) has emerged as a sustainable refrigerant choice, particularly well-suited for smaller-scale refrigeration and air conditioning systems. Noteworthy for its low Global Warming Potential (GWP), propane presents an environmentally friendly alternative with a significantly reduced impact compared to traditional synthetic refrigerants. As a hydrocarbon, propane is a natural substance derived from fossil fuels or renewable sources, aligning with the growing trend toward sustainable and natural refrigeration solutions.

Its use in refrigeration, especially in domestic applications like household refrigerators and freezers, has showcased good energy efficiency. Importantly, propane is non-ozone depleting, contributing to its environmental compatibility. However, due to its flammability, safety considerations are paramount, and propane-based systems are typically designed with safety features to ensure secure handling and operation. The increasing adoption of propane reflects a broader industry shift toward more sustainable refrigerants, emphasizing both environmental responsibility and effective refrigeration performance.

A2L refrigerants, exemplified by R-454C, represent a pivotal advancement in the realm of refrigeration, strategically balancing environmental considerations with efficient cooling performance. Characterized by a low Global Warming Potential (GWP), A2L refrigerants contribute significantly to the ongoing industry-wide efforts to mitigate the climate impact traditionally associated with synthetic refrigerants.

Classified as “mildly flammable,” A2L refrigerants, including R-454C, present a safer alternative compared to more flammable categories, guided by established safety standards and guidelines. Positioned as part of the transition away from high-GWP hydrofluorocarbons (HFCs), A2L refrigerants align with evolving regulatory frameworks addressing climate change concerns. Beyond their environmental attributes, A2L refrigerants are designed to maintain or enhance the energy efficiency of cooling systems, further supporting sustainability objectives.

Importantly, A2L refrigerants do not contribute to ozone depletion, aligning with global initiatives for ozone layer protection. As these refrigerants become increasingly prevalent, their adoption underscores a commitment to a more sustainable and environmentally conscious approach to refrigeration technology.

Genesys Natural Refrigeration Solutions

Return to the beginning of refrigeration with CO2 (R-744) and ammonia (R-717) systems

Global Warming Potential of 1

CO2 and ammonia are the gold standard for ozone depletion potential (ODP) and global warming potential (GWP). Neither are ozone depleting (0). CO2 has a GWP of 1—which is because it is used as the baseline for that scale—and ammonia has a GWP of 0.

Future Proof

For performance, CO2 is known for its high cooling capacity, and ammonia has a reputation for excellent energy efficiency. Natural refrigerants are a future-proof solution that exceeds modern sustainability goals, allowing customers to make the best choice for themselves and for the environment.

Zero Zone In Action

Zero Zone is proud to be a part of the U.S. Environmental Protection Agency’s (EPA) Advanced Refrigeration Partnership for over 15 years. We are also proud Gold Member and supporter of the North American Sustainable Refrigeration Council (NASRC).

Built in the USA


In the heart of the Midwest, Zero Zone is a manufacturer and assembler of refrigerated cases and systems. Zero Zone’s neighborly approach shines through as we proudly construct 90% of our cutting-edge cases using locally sourced components. This commitment to local suppliers not only ensures the superior quality and lead times for our products but also reflects our dedication to fostering a sustainable and collaborative community.