Zero Zone is incredibly proud of the hard work and expertise that John Collins, Industrial Sales Manager – East for Zero Zone, displayed in researching, writing, and presenting his technical paper, “Analysis of Package Chiller Systems – Comparison of Natural (NH3 & CO2) and HFC Refrigerants.” He presented it at the International Institute for Ammonia Research (IIAR) 2020 Virtual Conference, and he was awarded the well-deserved IIAR 2020 Award for Presentation Excellence – Food/Retail Refrigeration.
Collins thoroughly analyzed the data from 3 ice arena chillers that used different refrigerants in order to demonstrate statistically and strategically the advantages afforded by each refrigerant. Collins applied his study by presenting his findings as practical criteria that can help buyers choose a refrigerant that matches their goals and priorities for safety, cost, sustainability, serviceability, and more.
Collins also thanks his colleagues, Global Refrigeration Manager Masood Ali and Systems Engineering Manager Adam Ciesielski, for their insight and assistance in developing and reviewing the manuscript, and Zero Zone gratefully acknowledges their collaboration.
Not even refrigeration regulations are simple after 2020. Refrigerant regulations are changing, and getting new refrigeration equipment is complicated. This adds more challenges to stores, cold storage warehouses, pharmaceutical plants, and more.
Here is the brief summary of recent refrigerant regulations. The United States Environmental Protection Agency (EPA) issued SNAP Rules 20 and 21 in 2015 and 2016 to eliminate the use of refrigerants with high global warming potential (GWP), but those rules were vacated by the D.C. circuit court in 2017 and 2019. Since then, individual states have taken responsibility for issuing their own regulations. So far, most state regulations target the same high GWP refrigerants, but they have different effective dates and even define the effective dates differently. This creates a challenge for both buyers and manufacturers who need to know whether their new equipment will be compliant.
Zero Zone wants to help by providing the effective dates and a map so it is clear whether your state has any regulations. Check out our article about The State of Refrigerant Regulations. Please note that we recommend that our customers contact their state’s environmental regulatory department to clarify the nuances, but our research will be a valuable starting point.
“You asked, we answered.” That has been the motto for the Reveal Merchandiser® ever since it was launched in 2017. Through the years, we have expanded this product line again and again based on customer feedback, as you’ve seen with our Tall, MX, PX, and Hybrid™ options. And now, we are excited to announce that the Reveal Merchandiser® can be ordered (drumroll, please)… with doors!
Retailers sought a display case with the sleek design and merchandising flexibility of the Reveal Merchandiser® open multi-deck, but with the energy savings of a reach-in case. It was an open and shut case… Reveal™ with Doors to be exact. The Reveal™ with Doors case gives you all the merchandising capabilities you know and love about the standard Reveal Merchandiser®: deep shelves, deep bottom wire racks, beautiful ChillBrite® LED lighting, and equally versatile horizontal or vertical merchandising strategies. But, the best part? Reveal™ with Doors can lower energy costs by up to 71% compared to open multi-decks! Refrigeration equipment runs 24 hours per day, so there’s no denying, putting doors on cases significantly reduces energy costs and improves product shelf life.
Let’s talk about hockey. Or do you prefer figure skating? Maybe you’re a little nerdy (like us!) and want to talk about CO2 transcritical refrigeration. You are in luck, because the St. Michael-Albertville (STMA) Ice Arena has all of that!
The STMA story is about an ice arena that had too many skaters and not enough ice time to go around. The STMA School District replaced their existing system with a Zero Zone ColdLoop™ Ice Arena Chiller that cools both their original ice sheet and a new ice sheet. Terry Zerwas, the school’s Director of Buildings & Grounds, described the transition as “flawless,” and their Activities Director Keith Cornell spoke about how this gives the boys’ and girls’ hockey teams a real home. Their rink is ready for hockey players and figure skaters alike. “An Olympic skater had a program here,” explained Terry Zerwas, “and that Olympic skater found that it was the best that they had skated on.”
St. Cloud Refrigeration (SCR) was responsible for installing the ColdLoop™ Chiller. SCR Owner Mark Fitch says their relationship with Zero Zone goes back 40 years. “We’ve always been very familiar with Zero Zone’s equipment. They put together a very nice product for us.”
The design team chose CO2 as the primary refrigerant that works with a secondary glycol loop. Arena Manager Grant Fitch believes CO2 could be “the future” for ice rinks, and Mark Fitch is confident that “CO2 will be around and will not be phased out and will actually get bigger and bigger as time goes on.” CO2 is a very efficient and safe refrigerant. People question CO2 because it operates at very high pressures, but Mark Fitch says that is not a big concern. “Every component is built to deal with this pressure,” he states, comparing the system to other high pressure applications in homes and apartments. If high pressure is there, the system will be built to accommodate it.
You need a trusted refrigeration partner that will be there when you need them, help grow your sales, and save you money. So we think you’ll be interested in what a few of our retail partners have to say about why they chose Zero Zone.
Whether you prefer open multi-decks or reach-in display cases, Zero Zone has it all. “I’ve been in the grocery business for 51 years, and I think this is one of the best produce presentations I’ve ever seen,” a store manager said about the Reveal Merchandiser®. Regardless of whether you prefer open or reach-in, each of our cases is ready to deliver fresh products to your shoppers. Our white paper explains their merchandising strategies and the results.
You also need a quality refrigeration system to keep your product at the ideal temperature, and our retail partners benefit from our decades of experience with both large and small format stores. Refrigeration systems are complicated machines, but we pride ourselves on making them easier to install, operate, and service. This is how we deliver a high-quality product to you.
Most importantly, the foundation of our partnership with you is responsiveness. But don’t take our word for it. An operations director said, “Any time we reach out to Zero Zone, they’re Johnny-on-the-spot. They are there to answer any questions and help us out of any pickle we get into.” A store director said, “We couldn’t have asked for a better company to work with.” Read our “We’ve Got Your Back” white paper to see why these retailers chose to build a trusted partnership with Zero Zone.
The Crown Coliseum in Cumberland County, NC, is home to the Fayetteville Marksmen minor league hockey team. It also became the home to a brand new Zero Zone ColdLoop™ Ice Arena Chiller.
After years with an old R-22 system, Cumberland County turned to Zero Zone for a new chiller using ammonia. Ammonia is an industrial-grade refrigerant. “Ammonia as a refrigerant is an excellent choice,” Industrial Sales Manager John Collins explained. “It is perfectly suited for a low-temperature chiller application: highly efficient and very reliable.” Ammonia is a future-proof refrigerant with no ozone depletion potential (ODP = 0), no global warming potential (GWP = 0), and high performance. It is one of the most prominent natural refrigerants, which is appealing as an environmentally responsible option.
Cumberland County also chose many excellent cost-saving features: highly efficient screw compressors, evaporative condenser, PLC control system, variable frequency drives (VFDs), and, most notably, a heat reclaim system. Their heat reclaim system repurposes compressor discharge heat to warm the subfloor under the ice, ensuring that the subfloor will not freeze or crack. Heat reclaim systems repurpose the waste heat that otherwise would be released at the condenser without benefitting the arena.
Most importantly, the chiller produces high-quality ice for the hockey team. The Fayetteville Marksmen skate confidently because their home ice is formed by a ColdLoop™ Chiller.
You have great ideas for your stores, but it is challenging to bring them to life. As you consider the possibilities, Zero Zone is here to help, and the Zero Zone Technology Center is the place to get inspired. Picture this…
As you enter the building, you’ll be greeted with the sight of our main conference room through impressive double glass doors. As you continue walking, you’ll see a mural that honors our legacy of innovation, quality, and responsiveness. Turn the corner and admire a vintage Zero Zone freezer that operated for nearly 30 years.
Get your shopping carts ready! Just past the mural and vintage case, you will feel like you are stepping into a real grocery store. Our main showroom exhibits a fantastic collection of Zero Zone display cases for all applications, including frozen food, ice cream, beverage, wine, dairy, floral, bakery, prepackaged meat, fresh meat, bagged produce, and fresh produce. Compare how different products look between an open multi-deck and a reach-in display case. Black interior, white interior, different exterior colors, we have it! All of our main product lines are displayed—the industry-leading Crystal Merchandiser®, the robust Highlight Merchandiser®, and the sleek Reveal Merchandiser®. We also show off special case configurations such as Ultra Narrow, Back-to-Back, Rear Load, Tall, Meat Exclusive (MX), and Produce Exclusive (PX). And don’t forget about our fully operational Hybrid Merchandiser™, which keeps drinks cold for your visit.
Glancing around the main showroom, your eyes will fall on double stainless steel doors. Do we have more cases back there? No, it’s our systems showroom featuring our Edge™ XT (exterior) distributed system. This system is designed to be installed outside of your store, so it is built with heavy-duty steel housing to withstand the elements. Our systems showroom also gives you a glimpse at our extensive refrigeration system capabilities, which run the gamut of indoor and outdoor systems, large parallel systems and single compressor units, and a wide range of refrigerants, including CO2 transcritical and ammonia. Our experienced team is on the forefront of refrigeration technology, and our engineers have contributed to the IIAR’s CO2 Task Group and the ASHRAE Handbook.
Walking out of our systems showroom, you’ll see a door and a long hallway that you may have missed before. This leads to our state-of-the-art DOE Research & Development Test Labs. Our engineers are actively improving our products every day, and this facility is an impressive sight!
The Zero Zone Technology Center is a wealth of information and inspiration that you have to see for yourself. Whether you are looking for merchandising ideas and new display cases for your stores, or if you want a behind-the-scenes look at our innovation at work, let our refrigeration professionals help you find your inspiration at the Zero Zone Technology Center. Sneak a peek at our Technology Center Video and then contact your Zero Zone Sales Representative to arrange your visit. You’ll be glad you did.
Refrigeration engineers and service contractors need to understand the difference between bubble point (when a substance starts boiling) and dew point (when a substance finishes boiling) because high-glide refrigerants do not boil at a constant temperature. If refrigeration professionals do not know these terms or use them incorrectly, equipment will be inefficient and possibly be damaged. Let’s glide into this discussion about high-glide refrigerants.
Refrigerant Glide
Water boils at a consistent temperature. When you set a pot of water to boil, the water will boil at the same temperature whether the pot holds 1 cup of water or 2 cups of water. Even as the water evaporates, the remaining water boils at the same temperature. This is because the only substance being boiled is water.
Many refrigerants also have a consistent boiling point, whether they are natural refrigerants or synthetic refrigerants. But high-glide refrigerants do not boil at a consistent temperature. A high-glide refrigerant may start boiling at 18°F, but as it boils into a gas, the boiling point “glides” up to 28°F. Why does this happen? High-glide refrigerants are a blend of different refrigerants, and these refrigerants separate when they are brought to boiling. Since each refrigerant boils at different temperatures, they will evaporate into a gas at different points, which changes the composition and concentration of the remaining liquid refrigerant. This causes the boiling point to “glide.”
Let’s consider a high-glide refrigerant that is composed equally of three different refrigerants, and each boil at different temperatures; for example, 18°F, 23°F, and 28°F.
Below 18°F, the composition is completely liquid and not boiling.
At 18°F, the first refrigerant boils away. This changes the composition and concentration of the refrigerant blend, and the remaining refrigerants will boil at a higher temperature.
At 23°F, the next refrigerant in the composition boils away, changing the composition and concentration again.
At 28°F, the final refrigerant boils away. The entire refrigerant blend evaporates into a gas, and the boiling point “glides” up to 28°F.
Bubble, Mid, & Dew Point
For refrigerants without a glide, it is simpler to design a system because the refrigerant boils at the same temperature throughout the operation. But with high-glide refrigerants, the equipment could be designed for either when the refrigerant starts to boil (evaporate), when it has partially boiled, or when it has fully evaporated.
Refrigeration engineers and service contractors need to be familiar with the terms bubble point, mid point, and dew point.
Bubble point: Liquid refrigerant starts to boil at this pressure and temperature in the evaporator.
Mid point: Half of the liquid refrigerant has boiled away to a gas.
Dew point: The last of the liquid refrigerant boils away.
To remember these terms, think about how a liquid bubbles as it boils or how dew forms in the morning when water vapor condenses.
The terms bubble point and dew point need to be understood and applied when discussing high-glide refrigerants. If the equipment does not specify bubble or dew point, the contractor could operate it incorrectly. Bubble point and dew point can be very different, as seen in the previous example (18°F versus 28°F). Warning: If there is ambiguity about whether equipment was designed for dew point, mid point, or bubble point, ask the equipment manufacturer. Do not make assumptions and risk damaging the equipment by running it incorrectly.
Consider This
There are two things worth mentioning to further our discussion. First, the terms bubble, mid, and dew point must be applied differently when talking about condensers on the high side of the refrigeration cycle. The condenser starts at the dew point as vapor refrigerant begins to condense into a liquid, and it finishes at the bubble point as the vapor refrigerant completely condenses into a liquid.
Second, there are also low-glide refrigerants. Low-glide refrigerant blends do not separate as much as high-glide refrigerants when they boil, so the bubble point and dew point are closer together. However, even a small temperature difference affects how equipment is sized and used. It is still important to know the difference between bubble point and dew point for any refrigerant that has a temperature glide.
These are just the basics about temperature glide, but hopefully you can already understand the importance of knowing the terms bubble point, mid point, and dew point.
Using High-Glide Refrigerants
High-glide refrigerants are more complex because of the glide. Why would someone want their system to use high-glide refrigerants? These blended refrigerants were developed specifically to have less of an impact on the environment. Older synthetic refrigerants had high ozone depletion potential (ODP) and high global warming potential (GWP). Refrigerant manufacturers have developed high-glide refrigerants to have low or no impact on the ozone layer and global warming. High-glide refrigerants are gaining popularity because of this, but the glide leads to some new challenges when designing and servicing a refrigeration system.
Have questions? Contact us and ask for our Director of Regulatory Compliance & Refrigeration Technology.
We take our home refrigerators for granted. We put food into the refrigerator, and it makes the food cold. But actually, the refrigerator is not making the food cold; it is removing heat from the food. That might sound counterintuitive, so we invite you to open the door to the world of refrigeration by learning about the basics of the refrigeration cycle.
Heat Transfer & Pressure
Before we discuss the refrigeration cycle, we must briefly discuss heat transfer. Heat always transfers from warm to cold. You can see evidence of this in your beverage of choice. Your morning coffee may start hot, but as the day wears on, it gets cooler because heat transfers into the surrounding air. At lunch, your soda warms up as heat transfers from the surrounding air. This is called sensible heat transfer. You can remember this by thinking about how you can sense (feel) the change. The coffee mug feels hot as heat transfers to you; the soda can feels cold as heat transfers from you.
Heat transfer can also cause a substance to change state between solid, liquid, and gas. This is called latent heat transfer. For example, H2O can exist as a solid (ice), a liquid (water), or a gas (steam). At sea level, H2O will be water between 212°F (100°C) and 32°F (0°C). If water is heated beyond 212°F, it will evaporate into steam. If water is cooled below 32°F, it will freeze into ice. As a substance changes state, its original state will be reduced as the other state increases. For example, as ice melts, it disappears and the amount of water increases. If enough heat transfers, the substance will cease to exist in its original state. Latent heat transfer (changing state) takes more heat than sensible heat transfer (changing temperature).
Another factor is how pressure relates to temperature. Boiling points vary depending on the pressure surrounding the substance. At sea level, water boils at 212°F, but if you travel to Denver or Pikes Peak in Colorado, the atmospheric pressure is lower and the boiling point will be lower.
The Refrigeration Cycle
Your unfinished can of soda is now warm. How do you chill it again? You may think the answer is to add cold to it, but remember that heat only moves from warm to cold. It is more accurate to say that you are actually removing the heat from the soda by transferring that heat to another, colder object. This is the concept behind the refrigeration cycle.
The refrigeration cycle comes from the work of William John Macquorn Rankine, who discovered how to transfer heat away from objects that were already cool. Historically, this could be done by placing objects into an ice box. Ice works well as a refrigerant because it maintains a constant 32°F temperature. Warm product (milk, meat, etc.) transfers heat to the ice (latent heat transfer), causing the ice to melt into water. The water (full of heat) drains away, and the refrigerated space and product remain cool.
All modern refrigeration systems have four main components that work together to move heat: the evaporator, the compressor, the condenser, and the expansion device. Imagine that heat moves in a “bucket” and follow the bullet points which correspond to the figure.
The evaporator gathers/absorbs heat from the refrigerated space into a “bucket.” The “bucket” is low-pressure, and it changes state (latent heat transfer) as it absorbs heat. Then the evaporator moves the low-pressure, heat-filled “bucket” to the compressor.
The compressor applies pressure, which compresses the heat-filled “bucket.” The heat-filled “bucket” changes from low-pressure to high-pressure as the compressor pushes it from the colder evaporator to the warmer condenser. When pressure is added, the temperature of the “bucket” also increases.
The condenser takes the high-pressure, heat-filled “bucket” and releases the heat from the “bucket” to the outside air (or other application). The “bucket” changes state (latent heat transfer) again as it releases heat.
The expansion device relieves the pressure on the empty “bucket.” When pressure is reduced, the temperature also decreases. The “bucket” cools and expands on its way to the evaporator to absorb more heat again.
The downside of using ice as the “bucket” is that more ice must constantly be added as it melts away. Modern refrigeration systems needed a long-term solution. Refrigerants are the modern “bucket” because refrigerants can continually absorb and release energy without escaping the system. Refrigerants change state between a liquid to a gas. Refrigerants must be able to boil at low pressures and low temperatures to be efficient.
High-glide refrigerants have a unique effect on a refrigeration system.
Have questions? Contact us and ask for our Director of Regulatory Compliance & Refrigeration Technology.
Maybe you already know that high-glide refrigerants are mixtures of multiple refrigerants. Maybe you already know that the boiling point glides up as a high-glide refrigerant boils away, unlike traditional refrigerants. And maybe you can see that this complicates how refrigeration equipment is designed and operated.
But maybe this world of high-glide refrigerants is new to you. Or perhaps you are finding it difficult to explain these concepts to others. Zero Zone has developed a white paper that teaches the basics of refrigeration and shows the challenges with high-glide refrigerants.
High-glide refrigerants are gaining popularity because of their reduced GWP compared to non-glide refrigerants. We hope our observations help you operate your equipment more efficiently. Once you know the best practices for using high-glide refrigerants, you will find they are a great solution.
Have questions? Contact us and ask for our Director of Regulatory Compliance & Refrigeration Technology.
