Latin American wholesaler Makro, part of Dutch conglomerate SHV Holdings, has seen energy savings of up to 30% after transitioning from HFCs to CO2 (R744) refrigeration technologies, which it has done in eight of its 22 stores across Colombia.

The extent of energy savings depends largely on the store’s local climate, explained Rosmary Morales Acevedo, Regional Sustainability Manager at Makro, with savings varying from 10–12% in hotter cities to 30% in colder locales at higher altitudes.

By 2045, the company plans to have transitioned 80% of its stores to natural refrigerants through retrofits. While some stores will use propane (R290) plug-in cases, the preference is centralized CO2 systems, she said.

Morales Acevedo detailed Makro’s plans both during her presentation in the End Users Panel session and alongside David Osma, Project Engineer at Weston, in one of the Refrigeration Case Studies sessions at the ATMOsphere (ATMO) LATAM Summit 2023. The conference was held in Mexico City November 8‒9 and hosted by ATMOsphere, publisher of R744.com.

Colombia’s CO2 transition

Since Makro’s first CO2 installation in Colombia in 2017, the company has gradually been expanding its use of the technology in its stores. The converted sites range in size from 4,000 to 10,000m2 (43,055 to 107,639ft2), and systems offer cooling capacities of 50–80kW (14.2–22.7TR) for low temperature (LT) and 96–160kW (27.3–45.5TR) for medium temperature (MT).

The most recent project was the refurbishment of a 20-year-old store in Bogotá. The retrofit took place over a two-and-a-half-month period and includes both a central CO2 system and some standalone propane plug-ins. The new system, which was installed by the Colombian refrigeration manufacturer and contractor Weston, provides 80kW LT and 150kW (42.7TR) MT capacity.

Due to the varying operating conditions experienced across the country, some systems include additional technologies to boost performance, Morales Acevedo explained.

In colder climates like Bogotá, which is at an altitude of around 2,600m (8,530ft) above sea level, systems are in subcritical operation around 99% of the time. Meanwhile, in milder climates, like in Medellín, which is around 1,200m (3,937ft) above sea level, subcritical operation is achieved around 30% of the time and parallel compression can be added to improve efficiency.

In warm climates, like Valledupar, which is at sea level, systems are in subcritical operation around 5–10% of the time, and parallel compression is needed for similar performance to traditional refrigerants, she said.

In addition to energy savings, CO2 refrigeration can reduce end users’ carbon footprint, improve system reliability, reduce maintenance costs and improve corporate reputation, she added.

Despite some resistance against CO2 in the market, “success has been proven, showing there are no big risks,” said Morales Acevedo, adding that the transition will be an ongoing process.

Growing demand in LATAM

According to Osma’s presentation during the ATMO LATAM Contractors Panel session, technologies using natural refrigerants are going to become “more common” in the LATAM market, in part due to their “high versatility.”

Weston began working with natural refrigerants in 2017 with its first CO2 installation. It then partnered with German OEM and transcritical CO2 specialist TEKO in 2019 to broaden the adoption of the technology in LATAM. While it was difficult work to start with, partnering with TEKO has enabled Weston to be more competitive in terms of delivery times and prices, he said. TEKO’s perspective on the Latin American market was presented by its Managing Director, Andreas Meier, at ATMO LATAM 2023.

Initially, it was predominantly European-based supermarket chains with a regional presence that showed an interest in CO2 technologies. However, now Latin American chains are starting to engage and CO2 is becoming standard in Colombia, he added.

To date, the company has worked on around 40 CO2 projects, mainly the retrofit of large stores.

Weston also started working with R290 three years ago.

Challenges to overcome

To ensure the adoption of natural refrigerants in Latin America, several challenges must be overcome, explained Osma. These include the cost of converting production lines to meet safety standards, a lack of awareness among end users and suppliers, the affordability and accessibility of f-gases like Freon, cheap energy and a lack of highly trained personnel.

“We have our own installers [whom] we have trained up internally,” he said. “For the rest of the market, the Colombian government has a program to create awareness among installers and technicians with propane training. The government is supporting a lot [in Colombia], but that is missing in other countries.”

He also noted the demanding design conditions of tropical climates and a lack of government subsidies and incentives. As decisions are often made based on financial drivers, financial support would support the adoption of CO2 technologies, he added.

“We have our own installers [whom] we have trained up internally. For the rest of the market, the Colombian government has a program to create awareness among installers and technicians with propane training. The government is supporting a lot [in Colombia], but that is missing in other countries.”

David Osma, Weston