Whitepaper: Mitigating Price Increases of High GWP Refrigerants

| October 9, 2018

Under the F-Gas regulations, January 2018 sees the start of a sharp phase-down in the amount of HFC refrigerant that will be available to the EU market, with a reduction to 63% of the 2015 baseline figure. This is a steep reduction from the 93% availability in 2017 and the refrigeration industry is feeling the effects. The latter half of 2017 saw, for example, the price of R404A increase by 700%. R404A, with a GWP (Global Warming Potential) of 3,922 tonnes eq. CO2, is not alone in seeing these exceptional price increases. It is one of a group of gases with a GWP >2,500 that will be banned from use in stationary refrigeration equipment from 2020 (excepting equipment designed to cool below -50°C). This list includes R507, R422A, R422D, R434A and R428A.

The rising prices are not, however, restricted to these gases. R134a, with a GWP of 1,430, has also seen increases in the region of 400%, with a similar situation for many other commonly used refrigerants including R407C and R410A.

2018’s reduction in HFC availability is expected to see prices continuing to increase. Whilst some commentators have been vocal in their criticism that industry has not sufficiently prepared for the changes driven by F-Gas, the lower GWP refrigerants that can be used as replacements, including HFOs and HFO/HFC blends, do not carry the same comparatively low price-tag that the industry was used to previously. Higher refrigerant prices are expected to become a global phenomenon as producers struggle to meet end-user requirements whilst staying within their production quota.

Standards for refrigerant leaks

Leaking refrigerant becomes ever more expensive. It has been estimated that in many cases the cost of refrigerant loss is now higher than the cost of a technician’s time to repair a leak.

F-Gas does mandate that permanent leak detection systems be installed on large systems containing a refrigerant charge greater than 500 tonnes eq. CO2. There are also reductions in the frequency of leak checking requirements if permanent leak detection is installed for refrigeration systems containing greater than 5 tonnes eq. CO2. The regulations do not however provide any guidance as to the type of leak detection systems that can be used nor their respective capabilities.

Historically much of the installed base of leak detection equipment has been targeted at meeting code requirements from refrigeration safety standards such as EN 378:2016, which is in its requirements around refrigerant leak detection is broadly similar to other internationally used refrigeration standards including 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 EN 378:2016 are that the concentration at which a leak must be detected is relatively high for refrigerants of A1 safety classification, running upwards of 15,000 ppm (parts per million) in many cases. By contrast, ASHRAE 15 determines a detection level of 1,000 ppm for many of these A1 refrigerants. Either way, in most refrigerated spaces or machinery rooms, reaching these levels would require a catastrophic leak of a large volume of refrigerant.

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.

Reducing refrigerant leak rates

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 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 centralised 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.

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 150 kg of R404A would leak over the course of a year. In the current market, that equates to thousands of Pounds, or Euros, 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 say four points of detection to be in place on one zone, thereby allowing these points to be placed at the locations in the system most likely to leak. This includes 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 ~1,000ppm. 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-10ppm levels (notably, this is 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.

Refrigerant management solutions

The return on investment from leak detection can now be measured in months, not years. In many instances, the detection and repair of a single small yet significant leak can pay back the investment in leak detection in a single hit.

As important and valuable as it can be to detect a refrigerant leak before it becomes a larger, more expensive issue to resolve, doing so is of no use unless something is done to initiate action to repair the leak.

In order to make best use of a highly effective leak detection system in order to mitigate the rising cost of refrigerant, it must be integrated with a system that is able to alert appropriate personnel to the leak event and initiate a repair procedure. This can be achieved through a BMS/ BAS, though is increasingly being manifested through dedicated refrigerant management software.

Such software solutions are able to offer additional benefits. By tracking each individual refrigeration asset, it is possible to see patterns and trends of which asset or type of equipment is typically the cause of most leak events. This data can in turn be used to drive a preventative maintenance programme to help stop issues before they arise.

Tracking and recording refrigerant use per asset, and per site, is another powerful tool for reviewing refrigerant use across a multi-site enterprise. The data is a regulated reporting requirement, but again has use in determining trends to initiate proactive leak rate reduction measures.

It should also be noted that effective reduction of leak rates can also have a strong impact upon the energy efficiency and effectiveness of a refrigeration system, further contributing to cost savings.

Mitigating refrigerant price increases

The rapid increase in refrigerant prices shows no signs of abating, with further phase-down of HFC availability due through to 2030. As important and effective as they are and remain for refrigeration safety monitoring, many leak detection systems offer no solution in the battle to mitigate these rising costs by reducing leak rates.

Solutions are readily available and field-proven to deliver leak detection with a short ROI period, measuring at a level that can be used to drive an effective refrigerant management programme, integrating with the systems and software needed to make effective use of the data gathered and to alert quickly in the event of a leak. The case for implementing these solutions is growing ever faster, not only from an environmental perspective but with regard to the escalating operational costs and expenses. The focus is sharpening on leak rate reduction.

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