Having an A energy rating means the slightest heat gets trapped in the new Drago Towers, making it uncomfortably warm at night this time of year.
As such I've had to have the AC going to keep Mrs D at a sensible temperature, as she can be quite ill if she gets too hot with her MS.
The AC is very economical to run (I run it in reverse in the winter like a heat pump, much less expensive than running the hesting), but there is an irony in having to run something on electricity as a result of a houses A rated energy efficiency.