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Project Launch: 12/01/2017

Partner: Slipstream, Alltemp

Slipstream assessed the energy use and performance impacts of using an alternative refrigerant product in commercial walk-in coolers and freezer refrigeration systems.


This pilot focused on commercial customers with walk-in cooler and freezer refrigeration systems using HFC blend refrigerant R-404A. Alltemp-M refrigerant is marketed as a replacement product for R-404A, as 404A is now discouraged for use in retrofits due to its high global-warming potential.

In early 2018, Slipstream recruited five sites for the pilot, including three quick-service restaurants and two hotels. Among these sites, seven systems were selected for testing, including four walk-in freezers and three walk-in coolers, all using R-404A. Monitoring of the systems included measurement of refrigeration system electrical energy consumption; temperatures of the freezer or cooler interior, the room area near the freezer or cooler, and outdoor temperature for systems with outdoor condensers; and freezer or cooler door opening times.


Slipstream found that the capacity of both coolers and freezers was reduced when using the alternative refrigerant, and energy savings varied greatly across the five systems tested. Also, the manufacturer-recommended conversion procedures and pressure-temperature tables for Alltemp-M were inadequate at the start of work. Full results can be found in the final project report, available upon request. The Emerging Technologies Team has taken lessons learned during this project into account when presented with new alternate refrigerant products as energy-saving opportunities.