Indoor leakage test for safety of R-290 split type room air conditioner

Hydrocarbon refrigerant charge limits for quiescent rooms

“…Other work (e.g. Jabbour and Clodic, 2008;Zhang et al, 2013;Li, 2014) involving measurements of room floor concentrations (𝐶 𝑓𝑙𝑜𝑜𝑟 ) due to releases of R290 (propane) from AC units were shown to be significantly lower than what was inferred by the formula (used in IEC 60335-2-40), provided the release height was above around 0.6 m from the floor. It is noted that the formula used an assumption of fixed flammable volume-time and except for the general information that this was quantified using CFD, no details of their calculation procedures were given.…”

General framework for revising class A3 refrigerant charge limits – a discussion

“…It has been widely reported that the ACL formula in IEC 60335-2-40 is restrictive when applying it to common room air conditioning and air-to-air heat pump systems (e.g., Corberan et. al, 2008;Li, 2014;Vonsild, 2012;Zhang et. al., 2013).…”

An experimental viscosity investigation on the use of non‐Newtonian graphene heat transfer nanofluids at below‐ambient temperatures

“…80 Some of these refrigerants, however, give rise to flammability and safety hazards issues. 81,82 In supermarket applications, for example, one way to overcome such a situation (ie, flammable and toxic refrigerant circulating within the supermarket premises) is to operate with an indirect refrigeration system, 83 where the refrigerant loop is confined to a remotely located machine room, thus allowing for better safety hazard control and a significant reduction on refrigerant charge. Supermarket public areas (with refrigerated display cases, walk-in coolers, and freezers, and so on) are then served through a secondary fluid loop, 84 in which coolant fluids such as water or aqueous mixtures have an important role due to the nominal values of their thermophysical properties.…”