Aircon research - what's the deal with COP, 4-ticks (is equivalent to 1 lice?) and all those numbers?

Been delving into some technical statistics and specs about different aircons and calculating their COP (rated) as well as their minimal consumption. This applies only to Inverter system aircons.

I have 3 rooms to cool - Master bedroom (about 2.75kW needed), Study (2.2kW needed) and Spare room along corridor (2.2kW needed), for a total capacity of about 7.15kW needed

This is the expected usage pattern: Masterbedroom will be on for sleeping at night when needed, and perhaps up to 4 times a week during the daytime afternoons. Study aircon will be used much less often, and Spare is not foreseen to be used for the next 3 years. In any case, the scenario of max capacity being used is very unlikely, given the Study will never be used together with Masterbedroom. Thus, expected usage will top out at about 5kW max.

I did some analysis of quoted power consumption and capacity figures from brochures and PDFs I managed to get hold of:

So how do I read this $%^#$ thing? :)

Well, we can conclude the Starmex is good for high capacity cooling. The starmex is the highest-rated capacity model of all, and is good for rapid cooling and for higher capacity requirements. However, its base COP of 3.11 makes it inefficient at maintaining set temperatures (which is probably the aircon's operation functional for 4-5hours out of 7 hours of sleeping at night). This is due to its minimum power drawn being 0.45kW, much higher than the 0.3kW-0.34kW quoted by other brands, for a similar min capacity of 1.4kW-1.5kW of cooling. Conclusion: The Starmex is a good aircon system, but not the best at everything, just very well-advertised :)

So, from the chart, which is the Aircon System-3 to get? The Hitachi. Turns out it has the highest rated COP AND Min. COP. It's COP for cooling 2 rooms is decent too - 3.81, and on-par with the Starmex. Just don't ever switch on all three units at overdrive rapid-cool full blast with this combi :) it drops quite badly compared to the other models, not that 2.73 is really bad, but, given its unlikely this scenario will occur, I wouldn't worry too much about it.

So the important thing when getting an aircon system is - know your usage patterns, and capacity required.