As more and more businesses consider replacing their conventional refrigeration systems with low-charge ammonia technologies, they are increasingly seeking information about what such a switch entails.
The International Institute of Ammonia Refrigeration (IIAR) is seeking to meet that demand with new guidelines designed to help users safely install, operate and maintain ammonia refrigeration systems that use a charge of 500 lbs or less (and under 100 lbs in the next step). These guidelines, called Ammonia Refrigeration Management – Low Charge (ARM-LC), are a scaled-down version of the ARM guidelines the IIAR had previously issued for ammonia systems using charges of between 500 and 10,000 lbs..
The overarching goal of the ARM-LC guidelines is to help end users comply with the General Duty Clause of the Occupational Safety and Health Act, which requires that a place of employment be “free from recognized hazards.”
Peter Thomas, president and senior engineer, Resource Compliance Inc., and the author of the ARM-LC guidelines, outlined the document at the IIAR 2018 Conference & Expo in Colorado Springs, Colo., last month. The guidelines are currently being reviewed before final publication, which is expected to occur by the end of the year.
The good news for operators seeking to convert to low-charge ammonia refrigeration is that under ARM-LC equipment manufacturers and contractors will likely shoulder most of the work involved in the safe operation and maintenance of these systems, which have ammonia charge to capacity ratios of 0.5 lb/TR to 7 lbs/TR (compared to 20-30 lbs/TR or more in conventional systems).
“For the owners, probably the most important thing they can do, outside of selecting the system that they’re going to install, is selecting a good, qualified contractor,” he said.
Under the guidelines, contractors that install low-charge ammonia systems will still be responsible for training their on-site employees, although the training would be significantly less intensive that for large, industrial facilities that use bigger ammonia charges.
“Bringing an ammonia system to a site, even a low-charge system, still represents a new hazard,” Thomas explained. “Ammonia does have certain hazards, and employees need to be aware of that.”
Training of employees should be relatively simple, he said, and should revolve around a few key areas:
- The safety hazards of ammonia.This should be similar to safety hazard training offered for other refrigerants, Thomas pointed out. “This is not really a new category of training, but it’s adding a new chemical to a category of training that should already be taking place,” he said.
- Monitoring the system. Employees should be aware of what situations fall outside of normal operational parameters and require a phone call to the contractor.
- Steps to take in an emergency. If there is an accidental release, training should detail what steps should be taken.
Thomas said the ARM-LC guidelines recommend an audit of the system every five years, which he described as a fairly straightforward process. The document also includes templates that operators can use to create their own maintenance and operational procedures.
“For the owners, probably the most important thing they can do, outside of selecting the system that they’re going to install, is selecting a good, qualified contractor.”Peter Thomas, Resource Compliance Inc.
Manufacturers will have a significant role under the guidelines proposed in the ARM-LC document.
For packaged systems — which are expected to be a significant percentage of low-charge installations — the ARM-LC guidelines suggest that manufacturers should conduct a hazard review before the equipment is installed, in lieu of the full-scale process hazard analysis (PHA) that would normally be conducted at facilities with large ammonia systems.
Although some site-specific factors come into play, such as equipment accessibility, “what’s being proposed in ARM-LC is drastically, drastically reduced,” compared to full on-site PHA, said Thomas.
For stick-built low-charge ammonia systems, contractors would help in the consideration of site-specific concerns, he said.
Similarly, manufacturers can provide operating procedures for all of the phases of the system, from the initial start-up to how to conduct an emergency shutdown. Manufacturers would also supply recommended maintenance schedules.
As far as emergency response programs, the ARM-LC guidelines recommend that users amend their existing emergency response action plans with recommendations about how to respond to the smell of ammonia. It should trigger a call to the contractor, first of all, and could include an evacuation plan.
The ARM-LC guidelines also detail how changes to low-charge systems should be handled. This is more likely to be relevant with site-built as opposed to packaged systems, Thomas noted.
“If there’s going to be a change to a small-charge system, those shouldn’t be done in a cavalier way — they shouldn’t just be done on a whim,” he said. “There should be a process that’s followed to make sure components are compatible with ammonia and so forth.”
Opportunities for ammonia
Kurt Liebendorfer, VP of Evapco, a maker of low-charge packaged ammonia systems, who is also chairman of the IIAR committee overseeing ARM-LC, described the document as an important step in the journey to present low-charge ammonia options to new end users “in a fashion that doesn’t scare the hell out of them.”
Also speaking at the IIAR conference, Liebendorfer outlined the opportunities for the increasing adoption of low-charge ammonia systems in a variety of industries, whether as a direct coolant or as the primary refrigerant in an ammonia-CO2 system, for example.
Businesses such as data center operators and pharmaceutical manufacturers in are eyeing low-charge ammonia systems, he said, as natural refrigeration technology tends to align with these businesses’ missions around sustainability.
Supermarkets and ice rinks have also begun to install ammonia refrigeration systems, he noted, and there are many opportunities in large cold storage facilities that historically have used larger ammonia charges, as well as opportunities in the HVAC industry.
“It’s all because there’s significantly less ammonia in these small-charge systems,” Liebendorfer said. “They’re safer to operate, maintain and work around.”
Liebendorfer outlined several of the benefits of low-charge ammonia systems, including reduced energy usage, faster installation, and the elimination of a central machine room. They can also accelerate and facilitate tax depreciation, compared with conventional systems, and can have lower lifecycle costs.
In addition, low-charge ammonia systems are “inherently safer technology,” Liebendorfer said, citing in particular the fact that extensive testing has already been done on packaged systems before they leave the manufacturer’s plant.
End users of packaged ammonia systems should face reduced risk of Occupational Safety and Health Administration (OSHA) violations and fines, he said. Most of the citations issued by OSHA in recent years have been related to inadequate process safety information and other violations that should be prevented through the testing and documentation provided by manufacturers of packaged systems, he said.
“If we’re expecting to bring our [low-charge] ammonia systems to new industries, we need to bring these available programs and documentation to the owner and allow him to manage it without having to be responsible for writing it himself, as is prevalent in the rest of the ammonia industry,” Liebendorfer said. “And they will definitely satisfy the requirements, and then some, of the General Duty Clause.”
In turn, he added, regulators “need to recognize the lower risks of low-charge systems.”
To read the complete article in the April 2018 edition of Accelerate America, click here.
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