Refrigeration contractor using PGM-IR to perform a refrigerant leak inspection in a supermarket.

Refrigerant Management: a Match Made in HVAC-R Heaven

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Cost of Refrigerant

Refrigerant Management Programs Deliver Compliance & Cost Savings

There are many elements that come together to deliver an effective refrigerant management program in a supermarket environment. This includes the combination of hardware and software to deliver effective compliance with EPA Clean Air Act (CAA) Section 608 record keeping requirements, ASHRAE 15 refrigerant safety compliance and the delivery of an effective leak rate reduction program.

This article looks at the recent changes to EPA CAA Section 608 in relation to leak rate reduction and at the types of refrigerant detection system typically utilized by food retailers. It also highlights how the data from leak detection systems can be used beyond regulatory compliance requirements and can drive reduction of refrigerant emissions and its associated benefits.

Changes in the Regulatory Landscape

Environmental drivers to reduce the use and subsequent emission of high global warming potential (GWP) refrigerants are seeing changes abound in both regulation and refrigerant costs. The effects do vary significantly on a global basis. For example, price rises in Europe during 2017 on R-404A have been quoted as being in the region of a 700% increase. Although the scale of refrigerant price increases have not been as drastic in the United States, they have risen significantly. Increases of 70-80% on R-404A can easily be tracked across 2017 from some major online retailers.

The focus on higher GWP refrigerant reduction has also seen the introduction of various new refrigerant blends into the market. These new blends provide lower GWP alternatives as “drop-in” replacements for gases such as R-404A and R-22. Many of the newer blends, such as R-448A and R-449A, contain HFO refrigerants in combination with HFCs. The market is also seeing a growth in use of 100% HFO refrigerants, such as R-1234ze. The pricing of the newer refrigerants is not however as low as the industry has been used to, meaning an increasing cost associated with top-ups following refrigerant leaks, almost regardless of the refrigerant in use.

The European F-Gas regulation is a key factor affecting this globally. The 2018 reduction of the total GWP of refrigerant quota that can be sold into the European market to 63% of the 2015 baseline level is stark. Naturally this affects the highest GWP refrigerants most strongly but is rippling its affect across all refrigerants and starting to have global impact. Changes are resultantly being driven as to what refrigerant types and in what quantities the gas manufacturers wish to make, further affecting the price positioning. These changes in availability begin to have a global affect.

New EPA Leak Repair Requirements

It is notable that effective January 1, 2018, EPA CAA Section 608 extended its requirements for maintenance, service, repair and disposal to cover all HFC and HFO refrigerants. Previously CFC and HCFC had been covered.

Further changes are coming in 2019. The following table describes different refrigeration applications, the applicable charge size, the frequency of leak inspection mandated and the leak rate thresholds. The leak checking must occur at the mandated frequency unless records can show that the leak rate threshold has not been breached for one year. This became effective January 1, 2019.

New refrigerant regulations bring changes to leak repair requirements in 2019.

The mandated leak inspections being mapped against the leak rate threshold is seeing an increased need for refrigerant tracking to become easier and effective on an enterprise-wide basis. A number of providers can now offer software packages that allow for online entry of refrigerant usage by asset, by region and by enterprise. This assists on a store level, while also facilitating an enterprise wide view on leak rates and the associated costs.

Refrigerant tracking meets compliance requirements but alone, however, does not drive any reduction of the leak rate – it only improves its visibility. In order to drive an effective reduction of leak rate, investment in suitable refrigerant detection technologies and systems can be invaluable.

Refrigerant Leak Detection Choices

Historically much of the installed base of leak detection equipment has been targeted at meeting code requirements from refrigeration safety standards such as ASHRAE 15. The goal of these standards is clear: ensuring the safe use of refrigerants, and the safety of personnel working with and around refrigeration systems. The ensuing requirements of ASHRAE 15 are that the concentration at which a leak must be detected is relatively high for refrigerants of A1 safety classification, a detection level of 1,000 ppm, determined for many of these A1 refrigerants. Either way, in most refrigerated spaces and machinery rooms, reaching these levels would require a catastrophic leak of a large volume of refrigerant.

Refrigeration contractor performing a leak inspection in a supermarket.Monitoring refrigerant leakage at levels of 1,000 ppm (or higher) can therefore be viewed as an effective way to enhance the safe use of refrigerants. It does not provide a method for catching smaller refrigerant leaks, which nonetheless can result in a significant and increasingly expensive loss of refrigerant.

Given the growing cost of replacing and topping-up refrigerant, implementing a strategy to reduce refrigerant leak rates is coming more sharply into focus. This cannot be achieved by using detection systems looking for leaks in the region of 1,000 ppm, as is often in place for refrigeration safety.

Low-level leak detection is available and field proven, with a number of manufacturers offering detection systems with a minimum detectable level in the region of 20-25 ppm. Fewer still have capability to measure refrigerant concentrations as low as 1 ppm. The benefits of successfully implementing a leak detection system capable of such low-level detection of refrigerant leaks is a central part of developing an effective refrigerant management strategy designed to reduce leak rates.

The instruments capable of low-level refrigerant detection are most typically aspirated systems, using a pump to draw a sample from the point of detection back through a tube to a centralized monitoring location. This allows for cost effective use of higher technology, normally a precision sensor based on infrared absorption measurement techniques. These systems have in the past, been viewed as being cost prohibitive in comparison to the lower cost diffusion sensors used for refrigeration safety applications. The immediate benefits to be gained in reducing leak rates, based on the current price of refrigerants, can be seen to offer a swift return on investment if effectively deployed.

The following is demonstrative of a refrigerant leak in a machinery room (or similar sized space) with even diffusion of leaked gas into the space.

Leak detection systems with an MDL greater than 25 ppm may fail to alert users to significant refrigerant losses.

As the example shows, a leak detection system that is not capable of detecting levels lower than 25 ppm could not be guaranteed to detect this significant leak, yet 330 lbs of R-404A would leak over the course of a year. In the current market, that equates to a significantly increasing cost of potentially thousands of dollars, in undetected lost refrigerant.

In reality, gas will not immediately diffuse to an even concentration within the space into which it has leaked. That will take some time. This demonstrates another important factor in detecting a leak, which is the placement and number of detection points.

Use of aspirated systems allows for multiple points of detection to be deployed in a space for limited additional cost. On large sites, with many zones to be monitored, this can be achieved by using “splitter” or “spur” kits on the end of each sample tube. In practice, this could allow for example, four points of detection to be in place on one zone. These points would be placed at the locations in the system most likely to leak, including valves, joints, flanges and other parts of the system subject to the changing pressures and temperatures that can cause mechanical stress.

Further monitoring for leaks can be successfully deployed in areas that would not offer a reasonable possibility of detection if using instruments detecting at levels of ~1,000 ppm. In practice this means that, for example, a supermarket store floor can be monitored for leaks from display cases and refrigerant pipework across a whole building. The ability to detect at sub-10 ppm levels (as mandated by the California Air Resources Board’s stringent Refrigerant Management Program) offers the opportunity to pick up small leaks even in large open spaces, furthering enabling leak rate reduction strategies to be successful. Technology with this capability exists in both fixed position and portable configurations, allowing permanent monitoring and fast location of these leaks.

Data Driving Repairs & Leak Reduction

Enterprises with best-in-class refrigerant-leak rates acknowledge this is the result of a refrigerant management strategy consisting of a dedicated internal team, a refrigerant leak-detection system with automated notifications, and responsive refrigeration service providers. Teamwork is required while data and an effective refrigerant management system is essential to monitor, identify and reduce refrigerant leaks.

Leak detection equipment provides a solution local to a site, however the skills and responsibility for refrigerant management are very rarely shared across individuals located at each site. To drive a proactive refrigerant management program, data from leak detection equipment and refrigerant tracking needs to be combined and collected into a centralized system where it can be analyzed and presented by a team of refrigeration engineers and managers.

Leak Events Webinar

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The short timescales legislated to repair leaks requires rapid action and close coordination between owners and contractors. An effective refrigerant management system combining refrigerant tracking and leak detection with automated analysis and notifications will provide the visibility of prioritized actions. Relevant information will be accessed anywhere, at any time, on any device and to anyone with valid credentials. By inviting contracted partners as users into such a system, enables activities to be coordinated, verified, reviewed and supported. A system that allows contractors to report and provide feedback on the work done helps to build strong relationships, ensuring all parties are compliant and saving money by reducing refrigerant consumption.

Further, investment into a refrigerant management system for collating this information together provides the opportunity to partner with service providers and consultants to manage refrigerant on behalf of the entire enterprise, freeing up valuable in-house resources to focus on strategic projects and initiatives to ultimately drive business forward and realize costs savings. 

Are you struggling with the latest EPA leak repair requirements or reducing your enterprise’s refrigerant leak rate? Let us know how you could benefit from a data-driven refrigerant management program in the comments below.

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