We had one of those close mornings when the humidity is nearly 100% but too warm for fog. Driving my wife's 2010 Prius, I closed the vents and windows and used the air conditioner to take out the damp but I had to stop at a busy intersection. As I came to a stop, the engine shutoff yet the AC remained cool because the compressor is not engine driven.
Unlike engine driven compressors, there are no seals, electric clutches, or belts. Instead of designing for the wide range of engine speeds, 800-6,000 rpm, the Prius electric compressor is optimized and draws on the same technology as refrigerators and home air conditioners which have become exceptionally efficient. By eliminating parts and seals, the Prius compressor sets a high bar improving reliability and efficiency. So the light changed and everyone moved out yet the Prius engine was not burdened by electric compressor load as the traction battery provided power.
In contrast, today's gassers and diesels have belts, electric clutches, and seals for their mechanically driven compressors. This robs power directly from the engine and limits where the compressor can be located leading to a cluttered engine compartment. In contrast, the Prius regenerative braking stored the power that ran the air conditioner compressor and fan when the car slowed and stopped with the engine off. But the Prius extends the options back into the house.
I saw a nice room air conditioner at Home Depot, 850W for 7,000 BTU, well within the range of my 1kW inverter. I still have to test the unit but it looks to be substantially more efficient than our 5,000 BTU window AC and perfect for Prius power during an outage. So we'll be cooler and save electric bills this summer.
Compared to gassers and diesels, the Prius air conditioning is exceptionally efficient and reliable. Unlike gassers and diesels, Prius integration with the house extends efficiency and saving other household bills. Once again, the Prius is going where gassers and diesels can not follow.
Bob Wilson