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Leveraging Predictive Maintenance in Commercial Refrigeration

JimMitchell_Blog_Image Jim Mitchell | Technical Manager of Customer Success

Emerson Commercial & Residential Solutions

Predictive maintenance is showing big promise in the HVACR market. I recently provided input for an article for ACHR The News that discusses how predictive maintenance technology is being used in the commercial and residential markets. You can read the full article, “Predictive Maintenance Brings New Potential to HVACR Service Market,” here.

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HVACR systems are becoming smarter and more connected using internet protocol (IP) networks and the industrial internet of things (IIoT). These allow the real-time monitoring of equipment, or predictive maintenance, which gathers data points from equipment to keep tabs on system performance in order to help reduce the likelihood of failure.

For HVACR contractors, this means identifying a problem before it causes a larger issue, so that maintenance can be done to prevent equipment negatively impacting food quality and safety or other operational imperatives. For instance, a refrigeration rack alarm may indicate an issue that can be addressed, preventing operational issues that could have a negative impact on multiple cases of perishable product or thousands of dollars in-store merchandise.

How it works

Drawing from a combination of equipment sensors and control system data, performance analytics can provide store operators and enterprise managers deeper insights for:

  • Real-time and historic operating conditions in their facilities and systems
  • Pressure, temperature and energy data to compare to established benchmarks for a single store, stores within a region or enterprise-wide
  • Enterprise-level and store-level dashboards and prioritized notifications

 

For an example of how this differs from a rack alarm scenario, let’s look at a display case analysis based on temperature sensor data. Performance analytics may detect an anomaly in case temperature deviations which, while still within safe ranges, could suggest the presence of a larger performance issue. Instead of being notified with an urgent alarm, operators can be alerted on their operational dashboards. This insight gives them an opportunity to investigate the issue at their discretion, and even potentially pre-empt a potentially larger issue. It’s important to keep in mind that timing is key.

This is also an example of how operational dashboards can help retailers to align maintenance and operational activities around performance. Today’s facility management dashboards typically break down the urgency levels of maintenance issues, as previously noted. By extending these dashboards also to include performance analytics, end users can gain a much deeper understanding of how their systems are performing and operators can take pre-emptive actions where they deem appropriate — not just respond only to systems where urgent problems are already present.

Equipped with this information, operators can receive advance notice of certain performance issues that may soon impact them — on which systems or pieces of equipment, and in which stores. Enterprise views quickly provide managers with visual snapshots of urgent and important issues across their store networks, while enabling investigation into specific assets in their respective facilities. Whether you’re a maintenance technician or an enterprise manager, operational dashboards help allow you to focus on those specific maintenance activities which may potentially impact performance in the near future.

A change in approach

Commercial refrigeration systems consist of many connected components — often originating from multiple vendors — designed to meet a wide variety of applications, ranging from coffin-style display cases to walk-in freezers. Industry macro trends further increase this complexity, including the adoption of new refrigerants and the migration from centralized to decentralized and stand-alone systems. Commercial contractors will need to do more than simply install connected sensors and devices; they will need to change their approach toward commercial refrigeration, including the ability to combine new technologies with deep experience within the context of widely varying system requirements.

Rather than focusing only on what is happening at any given moment in a location — whether that’s a low- or high-priority alarm — analytics can help operators gain deeper insights into issues that could have future operational impacts. Access to these insights helps operators transition to a condition-based, analytics-driven approach — one where they can take proactive steps, perform preventive maintenance, use resources more efficiently, and stop smaller issues from becoming larger problems — instead of a more reactive approach.

What to watch for

IIoT features new technologies that will likely result in operators being able to deploy interconnected devices more widely, potentially at a lower initial cost. These offerings may drive value for operators by causing significant energy savings, lower maintenance and service costs, and improved operator experiences.

At Emerson’s innovation centers and in customer field trials, we are working with our customers to tackle the challenges related to predictive maintenance head on. By modeling refrigeration applications, we have helped our partners take a more methodical, deliberate approach to predictive maintenance. Our goal is not simply to throw more IIoT at the problem, but to help provide true insights from the data while leveraging our deep intellectual capital and experience in the commercial refrigeration space. We believe this helps us deliver the transformative value that predictive maintenance represents. By doing so, we can be a part of simplifying the complex and uncover insights that are representative of the industry’s most common refrigeration scenarios.

For example, a typical refrigeration system or rack has alarms that identify current issues only, and slow leaks often can be difficult to discern from normal fluctuations. But with a machine-learning supervisory app, multiple models can account for variable operating envelopes with up to ~90% accuracy and identify leaks as many as 30 days before physical detection devices.

While it is difficult to predict five years in the future accurately, it is safe to assume that with the adoption of 5G technology and other advances in component miniaturization and cost reduction, solutions will continue to get smarter. With a flood of data occurring at both the enterprise level (reporting) and the device level (gathering data), we will need more intelligence in interpreting this information in order to help deliver better, more accurate results.

In the meantime, one thing that contractors can do is avoid the rush to recommend IIoT implementation that can result in applications which can create more “noise” — i.e., a barrage of events to monitor and triage — and trigger false errors or events that identify issues too early (or too late).

 

 

Information in this article was first published in ACHR The News, March 16, 2020.

Natural Refrigerants Remain Viable Among Emerging Options

AndrePatenaude_Blog_Image Andre Patenaude | Director, Food Retail Marketing & Growth Strategy, Cold Chain

Emerson Commercial & Residential Solutions

I was recently asked by the editor of Accelerate America to offer my opinion on the viability of natural refrigerants, including CO2 (R-744), propane (R-290) and ammonia (R-714). Among the many emerging refrigerant alternatives, natural refrigerants check important boxes for owners and operators who are preparing for the rapidly changing commercial refrigeration landscape. View the full article here and read a summary of its key points below.

For more than a decade, natural refrigerants have factored prominently in the search for environmentally friendly refrigeration in both commercial and industrial sectors. We’ve seen the introduction of R-290 in micro-distributed, self-contained cases; increased global adoption of CO2 in centralized systems; and the emergence of ultra-low-charge ammonia, by itself as well as integrated with CO2 in cascade systems. As we kick off a new decade, we will likely continue to see these refrigerants progress along those established lanes.

Drivers for natural refrigerant adoption

Since their introduction, the drivers for natural refrigerant adoption have not changed. Most legacy refrigeration strategies rely on the use of high global warming potential (GWP) hydrofluorocarbon (HFC) refrigerants, and companies with sustainability objectives or regulatory mandates were among the first to make the transition to natural refrigerants — which by many are considered immune from regulatory-mandated GWP caps.

In 2020, the phase-down of HFCs remains a focus of global environmental regulations. From the Kigali Amendment to the Montreal Protocol and the European F-Gas regulations to the California Air Resources Board (CARB) and Environment and Climate Change Canada (ECCC), many countries, states and regions share the goal of an HFC phase-down.

It’s often said that there’s no such thing as a perfect refrigerant — and that’s certainly the case with natural options. But natural refrigerants are among the very few alternatives capable of meeting some of the more aggressive GWP targets. R-290 has a GWP of 3; CO2 has a GWP of 1; and ammonia has a GWP of 0. So from environmental and regulatory perspectives, this puts them in a class by themselves.

Characteristics and caveats

With decades of field use and research to draw from, the performance characteristics of natural refrigerants are well known. But each option has operating caveats that equipment owners must carefully consider before investing in a long-term refrigeration strategy.

  • R-290 offers excellent energy efficiencies, but as an A3 (flammable) refrigerant, safety regulations limit its use to small charges globally from 150g to 500g. R-290 is a natural fit for small-capacity, self-contained cases that require a lower charge and are hermetically sealed at the factory.
  • CO2 is a high-pressure refrigerant with a low critical point (87.8 °F) that determines its modes of operation (subcritical, or below the critical point; transcritical, or above the critical point). It also has a high triple point where the refrigerant will turn to dry ice. Systems must be designed to manage these characteristics, and operators must have access to qualified technicians.
  • Ammonia has been used in industrial refrigeration for the past century, but its toxicity (B2L classification) presents challenges to equipment owners. Tightening safety regulations and the risk of exposure have led to system architectures designed to lower charges and move it out of occupied spaces.

Selecting a natural architecture

When evaluating natural refrigerant architectures, store formats and application requirements will often dictate the refrigerant choice. R-290 is well-suited for either smaller-format stores or as a spot merchandising option for larger stores. CO2 makes the most sense in larger stores seeking a centralized architecture alternative to HFCs. Ammonia is relatively rare in commercial applications but is finding its way into innovative architectures designed to mitigate its risks and benefit from its excellent performance characteristics.

R-290, from integrated cases to micro-distributed — For nearly a decade, manufacturers have worked within the 150g charge limit to create self-contained, integrated cases, in which the refrigeration system (compressor and condensing unit) is built into the display case. These evolved into a micro-distributed approach for small stores, where multiple units share a water/glycol loop to remove excess heat. This approach provides very low-GWP, total-store cooling while keeping charges low, typically operating with 90% less refrigerant than a centralized system.

CO2 transcritical booster — CO2 came into prominence more than a decade ago in large supermarkets where centralized architectures are preferred. CO2 transcritical booster system technology continues to improve today, offering an all-natural solution for both low- and medium-temperature cooling. Compared to centralized HFC systems, CO2 transcritical boosters represent a completely different approach to system operation and servicing. Operators must acquire technicians that are trained to service CO2 systems and implement strategies for power outages in order to mitigate “stand-still” pressure while the system is off.

CO2/ammonia hybrid subcritical (cascade) — CO2 cascade systems are designed to utilize CO2 in the low-temperature (LT) suction group where the refrigerant stays below its critical point and operates at lower pressures, much like a traditional HFC. Typically, an HFC (or HFO/HFC blend) is used in the medium-temperature (MT) circuit, where heat produced from the LT circuit is discharged (i.e., cascaded) into a heat exchanger and into the suction stage of the MT circuit. However, the recent introduction of ammonia as the MT refrigerant has transformed this configuration into an all-natural refrigerant option.

Safety first

With each of these natural refrigerant options, safety must be the primary consideration. Manufacturers have poured a great deal of effort into ensuring the safe operation and maintenance of natural systems with a variety of strategies, including pressure relief valves, specially designed components, leak detection devices, and proper guidance to owners and operators.

The global regulatory climate and trend toward environmentally friendly refrigeration will help natural refrigerants to proliferate along these well-established paths of least resistance. Still, there is much to consider for system operators, who must weigh the opportunity costs for selecting a natural refrigerant option.

 

How to Comply With DOE Standards on Walk-In Coolers and Freezers

Julie_Havenar Julie Havenar | Product Manager – Condensing Units

Emerson Commercial & Residential Solutions

In 2017, the Department of Energy (DOE) passed its final rule on new energy conservation standards for walk-in coolers and freezers (WICFs). The ruling mandated new efficiency requirements on WICFs with dedicated condensing systems in both low- and medium-temperature applications. With enforcement of these requirements now having taken effect, I recently published an article for Contracting Business that explained the implications of the DOE’s ruling. View the full article here and read a summary of it below.

Per the ruling, 20–40 percent energy reductions are now required on WICFs smaller than 3,000 square feet manufactured after the following enforcement dates:

  • January 1, 2020, for WICFs with medium-temperature dedicated condensing systems
  • July 10, 2020, for WICFs with low-temperature dedicated condensing systems

Now that enforcement dates are here, industry stakeholders are tasked with verifying that they are achieving compliance with the DOE’s WICF rule.

Who and what does the ruling apply to?

The ruling directly applies to anyone manufacturing, producing, assembling or importing to certify WICF components. From a refrigeration system standpoint, compliant components refer to dedicated and packaged condensing units (indoor and outdoor) used in both new and retrofit applications, including:

  • Condensing units that are assembled to construct a new WICF
  • Condensing units used to replace an existing, previously installed WICF component (retrofit)
  • Condensing units used within packaged systems

Other components — such as unit coolers (evaporators), doors, panels and lighting — are also within the jurisdiction of the DOE’s WICF ruling.

Contractors and wholesalers can still use and stock condensing units that were manufactured before the DOE enforcement dates for retrofit purposes. All newly manufactured condensing units must be compliant if intended for use in applicable WICF applications, as defined by the DOE’s ruling.

How can you measure efficiency and achieve compliance?

The DOE uses a metric created by the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) called the Annual Walk-In Energy Factor (AWEF) to evaluate a WICF system’s energy efficiency. This AWEF calculation is based on “a ratio of the total heat, not including the heat generated by the operation of refrigeration systems, removed, in Btu, from a walk-in box during a one-year period of usage for refrigeration to the total energy input of refrigeration systems, in watt-hours, during the same period.”

Per the DOE, there are several WICF equipment classes below the 3,000 square foot limit that must meet or exceed the minimum AWEF ratings based on capacity and application (e.g., medium- or low-temperature, indoor or outdoor). Condensing unit manufacturers and WICF original equipment manufacturers (OEMs) must follow approved AWEF testing and certification procedures to meet or exceed the DOE standards.

How will the ruling impact you?

From OEMs and wholesalers to contractors and end users, the DOE’s WICF ruling has broad impacts throughout the industry. Because the DOE WICF ruling impacts both new and retrofit equipment, every segment of the commercial refrigeration supply chain will need to understand its implications. Here’s what you need to know:

  • OEMs — need to complete the engineering design cycle, testing and certification to sell new compliant equipment.
  • Contractors — must understand that if they replace a condensing unit with one manufactured after the DOE enforcement dates, it must be an AWEF-compliant unit. However, units manufactured prior to the DOE’s enforcement dates already in inventory may still be used.
  • Wholesalers — must be prepared for changing inventories and begin to carry only AWEF-compliant condensing units that were manufactured after the 2020 enforcement dates for the relevant WICF applications.
  • Design consultants — must be well-versed in the regulatory impacts to advise end users in the selection of energy-compliant, sustainable systems.
  • End users — need to select future-proof equipment that aligns with their long-term refrigeration strategies.

How is Emerson helping OEMs?

As a manufacturer of condensing units for a wide range of refrigeration applications, we manufacture WICF condensing units that have been certified as meeting the DOE’s minimum AWEF requirements. Compliance data is listed in our condensing unit AWEF product literature.

For WICF OEMs, using certified condensing units will help them meet the compliance requirements in one of their primary refrigeration system components. OEMs should be able to combine an Emerson AWEF-compliant condensing unit with any AWEF-compliant unit cooler in order to achieve compliance in a dedicated system.

So if you’re an OEM of walk-in coolers and freezers, you now need to manufacture WICFs that meet the DOE’s minimum AWEF standards. If you’re not sure how to proceed with this compliance process, you may consult with Emerson’s Design Services Network to expedite your product development, design and testing processes.

With our breadth of products, expertise and resources, we can help you achieve compliance and develop sustainable refrigeration strategies for your customers — and our future.

 

Low-GWP Strategies for Achieving CARB Compliance

AndrePatenaude_Blog_Image Andre Patenaude | Director, Food Retail Marketing & Growth Strategy, Cold Chain

Emerson Commercial & Residential Solutions

Emerson was recently invited to participate in a webinar series hosted by the North American Sustainable Refrigeration Council (NASRC) aimed at helping retailers prepare for California’s refrigerant regulations and incentives. In the webinar, Diego Marafon, refrigeration scroll product manager at Emerson, and I discussed emerging refrigeration strategies for supporting low-GWP (global warming potential) compliance and hydrofluorocarbon (HFC) reductions while uncovering opportunities to lower operating costs.

Low-GWP Strategies for Achieving CARB Compliance

In the U.S., the California Air Resources Board (CARB) is leading the charge for regulations impacting commercial refrigeration. For large centralized refrigeration systems — which today make up the majority of retail refrigeration — CARB’s current proposal would require new systems with more than 50 pounds of refrigerant to use refrigerants below 150 GWP. As a result, CO2 is a primary refrigerant choice for operators seeking to stay with a large centralized system and meet CARB’s proposed regulation.

But as retailers evaluate new system architectures, they also have an expanding variety of decentralized and distributed options to consider. What’s more, CARB’s latest proposals provide new approaches for achieving HFC reductions that are giving retailers the option to remodel, rather than invest in all-new refrigeration systems for their fleet of stores. These proposals include:

  • Greenhouse gas emission potential (GHGp) reduction by 55% — Requires the total GHGp of all refrigeration systems in all stores to be 55% below the 2018 baseline by 2030, where GHGp equals the sum of the refrigerant charge times GWP — or GHGp = ∑(charge X GWP). This is a per-company target which gives retailers some flexibility in achieving compliance. As retailers retrofit their stores, they’ll receive credits for refrigerant charge and GWP reductions. But retailers must have the abilities to track, report each store’s GHGp baselines as well as document and verify any equipment changes.
  • Weighted average GWP (WAGWP) reduction < 1,400 — Requires the WAGWP of each retailer to be less than 1,400 by 2030. It’s calculated by finding the sum of the charge times GWP in every system in every store, divided by the total charge — or weighted average GWP = ∑(charge X GWP) / ∑ This approach allows retailers to aim for a fixed target — without the need for tracking a company baseline — while giving them the option to only retrofit the stores needed to meet the 1,400 GWP target. Retailers may need to apply this equation to multiple retrofit scenarios to successfully deploy this strategy. Simply put, they’ll need to do the math and figure out how to best reach this target.

Weighing your retrofit options

In the webinar, we discussed each of these approaches and ran the numbers to show how retailers could take a long-term view of their store fleet strategies and make modifications to achieve their goals — utilizing refrigerant changes, system retrofits or installing new refrigeration systems. Using a WAGWP calculator developed by Emerson, we demonstrated different strategies for achieving CARB compliance, providing cost projections for each option. If you’re interested in learning more about the WAGWP calculator, you can contact your salesperson, or visit the contact us page.

For this exercise, we looked at a hypothetical scenario of a California retailer with 25 stores, 66 total refrigeration systems and a WAGWP of 2,715. Then we evaluated three different retrofit options and calculated their impacts:

  • Refrigerant change from R-404A to R-448A — By changing out the refrigerant in all 25 stores, the retailer could achieve a WAGWP of 1,383 (nearly a 50% GHGp reduction). The total CapEx for the changes were $3M, with a cost per WAGWP reduction of $2.2k.
  • Convert half the stores to a new CO2 system — By installing new CO2 systems in 12 of the stores and leaving the other 13 untouched, the retailer could achieve a WAGWP of 1,277 (or a 54% GHGp reduction). The total CapEx for the changes were $27.3M, with a cost per WAGWP reduction of $19k.
  • Hybrid approach — By converting 20 systems to R-448A and installing 28 new scroll booster systems (with R-513A) — leaving 18 systems as is — the retailer could achieve a WAGWP of 1,520 (or 55% GHGp reduction). The total CapEx for the changes were $15M, with a cost per WAGWP reduction of $13k.

These scenarios demonstrated how to calculate system retrofit and remodel impacts while showing the multiple alternatives for implementing lower-GWP remodel strategies. It’s important to realize that in California, CARB has incentive programs to help retailers offset the cost of making these system changes.

But CARB is just one piece of a dynamic regulatory landscape — which includes energy, environmental and food safety regulations within varying regional, national and global jurisdictions — that continues to drive changes in refrigeration equipment and architectures. In response, Emerson is committed to developing a full spectrum of low-GWP refrigerant technologies, including CO2, R-290 and hydrofluoroolefins (HFOs), as well as lower-GWP HFC A1 refrigerants that are still in use. Most recently, we’ve expanded our offerings to support the industry’s need for more flexible, distributed architectures which deliver both high energy efficiencies and low-GWP ratings.

To learn more about using Emerson’s tools for calculating the impacts that system retrofits or remodels would have on your store fleet’s environmental footprint, view this NASRC webinar with the title of, “Emerson Technology Solutions.”

 

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