Potential replacements for current hydrofluorocarbon (HFC) refrigerants include pure and blended hydrocarbon refrigerants since they have a lower global warming potential (GWP) and comparable working fluid properties.
The current barrier to a broader application of these refrigerants is their classification as flammable A3 substances according to ASHRAE 34. As a result, their use is accompanied by additional design constraints to minimize safety hazards.
A current design constraint for A3 refrigerants is a 150 g charge size limit in portable unit systems.
The objective of this project was to understand the severity of ignition events involving R-290 (propane) at charge sizes above the current limit of 150 g to evaluate the viability of class A3 refrigerants as replacements for HFCs in more HVAC&R applications.
