Scantec Low-charge Ammonia
Scantec Refrigeration Technologies low-charge ammonia system installed in 248,000m3 refrigeration plant in Melbourne, Florida. Photo credit: Scantec.

Scantec Refrigeration Technologies Sees Rise in Demand for Its Low-Charge Ammonia Systems, Says Managing Director

Stefan Jensen spoke to about what’s driving the demand for low-charge ammonia refrigeration.

When it comes to projects, Scantec Refrigeration Technologies, an Australian provider of centralized low-charge ammonia (R717) refrigeration systems, has a “full order book for the 2024‒2025 financial year and a little beyond,” according to Managing Director Stefan Jensen.

The rising demand Scantec is seeing for its low-charge ammonia systems with direct expansion feed comes from three sources, Jensen told Jan Dusek, ATMOsphere’s Co-Founder and COO, in an exclusive interview. ATMOsphere is the publisher of

Those sources are rising electrical energy costs, Australian refrigeration consultants and word of mouth in the cold storage industry.

In a 2021 ATMOsphere interview, Jensen predicted that these systems would continue to gain momentum “simply because the energy efficiency – when designed correctly – is superior to all other refrigeration concepts.”

The company currently operates with roughly 40 employees and produces eight to 25 low-charge ammonia systems annually, depending on project sizes, Jensen estimated.

“If we are talking about smaller projects, using our prepackaged ScanPAC, we can squeeze through 20 to 25 jobs a year,” he said, noting that if it’s larger stick-built systems that require construction on-site, the estimate drops to eight to 10.

Using less energy

As part of a different company, Jensen participated in developing the first Australian low-charge ammonia systems with direct expansion roughly 30 years ago, with an initial installation in a Brisbane suburb in the early 1990s.

Jensen said Scantec’s low-charge ammonia systems with direct expansion offer a sizable savings in energy consumption compared to “industry-standard systems” using HFC refrigerants.

“When we replaced an air-cooled R404A system with a dry expansion ammonia system, the energy consumption went down by around two-thirds, providing a simple payback period in the order of five years,” Jensen said, referencing an address he gave at the 2019 International Congress of Refrigeration, held in Montreal. The presentation outlined a refrigerated warehouse retrofit case study in Mackay, North Queensland.

When it comes to comparing conceptually identical ammonia systems with a typical engine room on the ground floor and ceiling-suspended evaporators – with the only difference being the refrigerant feeds – the dry expansion feed system consumes about 30% less energy than a liquid overfeed one, Jensen said, with three-to-five times less ammonia charge.

Jensen has said that customers have seen the performance figures and felt they were too good to be true. “It’s hard to get the message across and be believed … even with energy performance data from 30 systems,” he said during a presentation at the ATMOsphere APAC Summit 2022.

“We’ve gained some traction, with approximately 40 commercial systems now operating in Australia,” Jensen told Dusek. “We are seeing refrigeration consultants and academics using our figures in presentations. We are seeing plant specifications for low-charge systems with the refrigerant injection controlled by a combination of quality and superheat sensors. That’s straight out of our playbook.”

Recently, Scantec was awarded a new job in Malaysia, Jensen said, with the “word-of-mouth” lead coming from another Malaysian cold storage operator in Penang.

“Before installing the system in Penang, we predicted an annual energy usage of 11kWh per cubic meter,” Jensen said. “The system is delivering 8.5kWh per cubic meter a year, which is around six times better than another plant that the company owns that uses a conventional liquid overfeed system with screw compressors.”

Another way the company saves on energy is by using reciprocating technology, Jensen said, adding that SEC drops by around 30% when using reciprocating compressors compared to screw compressors in dry expansion ammonia systems that are subjected to the load variations normally experienced in cool and cold storage applications.

Installation ranges

Scantec supplies refrigeration systems for refrigerated warehouses and large-scale food factories in the Oceania region.

For facilities with smaller refrigerated volumes ranging from 3,000 to 7,000m3 (105,944 to 247,203ft3), Scantec offers transcritical CO2 (R744) systems using Danish OEM Advansor packages, Jensen said.

For volumes over 7,000m3, the ScanPAC ‒ a containerized, low-charge ammonia system manufactured by Scantec with three or four compressors ‒ lowers costs by reducing the time spent on-site, Jensen said. The largest individual ScanPAC unit can service refrigerated storage volumes up to approximately 100,000m3 (3,531,467ft3), with multiple packs meeting the needs of larger facilities. The service volumes refer to storage only, with no blast freezing.

The largest low-charge ammonia system manufactured and installed by Scantec so far was for a chicken processor at Truganina in the Australian state of Victoria, with a total refrigerated volume of 248,000m3 (8,758,037ft3), Jensen said. Earlier this year, the company commissioned a system for a distribution center near Perth with 73,000m3 (2,577,971ft3) of refrigerated space. Early next year, Scantec will complete another distribution center in the same area that will be serviced by a centralized, low-charge ammonia refrigeration plant.

Jensen told Dusek that the company recently introduced low-charge ammonia refrigeration to the abattoir market, installing a system in a Tasmanian slaughterhouse. “I think it is a first in any abattoir worldwide,” he said. The system is presently being expanded with an additional batch blast freezer.

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