Low GWP working fluids are important for eco-friendly systems, but their flammability is a concern. Ignition energy affects how easily they catch fire. Testing different fluids, researchers found that higher ignition energy makes them less likely to ignite at low levels but more likely at high levels. The impact varies between fluids, with R1243zf being the most affected. Ignition energy mainly affects the initial flame, not the burning speed. This research helps make using flammable fluids safer.