ATMO LATAM: Mexican Contractor SRT Sees Propane as Immediate Solution for Medium-Temperature Applications

Mexican contractor Sistemas de Refrigeración Totales (SRT) sees propane (R290) as an immediate solution for medium-temperature applications, both as a primary refrigerant and to subcool CO₂ (R744), said Fernando Rios, Head of Natural Refrigerants and Services at the company.

“We can use propane as a direct refrigerant with large equipment, an indirect refrigerant with a glycol loop and as a secondary refrigerant to condense a CO₂ system at low temperatures,” Fernando said.

Fernando, joined by David Rios, General Director of SRT, outlined the company’s use of R290 and its training initiatives in a presentation at ATMOsphere (ATMO) LATAM 2025. The event was held February 19‒20 in Mexico City and was organized by ATMOsphere, publisher of NaturalRefrigerants.com.

Primary: SRT installed an Ice-Square R290 chiller for 0°C (32°F) storage of approximately 30 metric tons of raw material in a Grupo Bimbo (a Mexican multinational food company) facility in Azcapotzalco, Mexico City.

• A −8°C (17.6°F) glycol secondary loop cools the chamber. However, SRT also installed air coolers inside the storage room to assist with defrosting.
• The system uses variable frequency drive on the main compressor, an electronic expansion valve and plate heat exchangers.
• “In this project, we prioritized a low refrigerant charge and operator safety,” David said, adding that the system uses stainless-steel piping with press fittings to prevent leaks.

Secondary/training: In March, the contractor was in the final stages of installing an Ice-Square R290 chiller in a mini market application, with support from SEMARNAT (Mexico’s Ministry of Environment and Natural Resources) and GIZ (German Society for International Cooperation).

• The unit uses a dry cooler with glycol circulating at −10°C (14°F) to condense a CO₂ system in cascade and maintain the temperatures in refrigeration chambers between −2 and 0°C (28.4 and 32°F).
• The cascade system and dry cooler use Copeland scroll compressors with inverter technology.
• “This system, with clear acrylic doors on all sides, will be used for training technicians on R290/CO₂ cascade systems,” Fernando said.

CO₂ training: SRT also works with the CO₂ Training Center Mexico in Tepotzotlán, Mexico, in conjunction with Green NatRef Mexico, a marketing and consulting organization launched in January 2024.

• “We’re trying to offer all of the solutions so a client doesn’t have excuses,” said Fernando, who also serves as a coordinator at the CO₂ Training Center.

Quotable: “If it is properly managed, propane is one of the safest refrigerants available,” said David. “It is very similar to HFC refrigerants, with similar pressures. All we have to do is apply flammability safety measures.”

“If it is properly managed, propane is one of the safest refrigerants available.”

David Rios, General Director of SRT