Friday night I met a guy called Alex, who is, if I remember correctly, an environmental engineer from East Anglia University (the respective faculty there became (in)famous for the ClimateGate scandal on leaked emails). It was my understanding that he is currently working in a program helping Bangladesh prepare for adaptation to climate change, so not exactly what we are doing.
However, I told him about the problem of baseline identification in the AC scenario, i.e. that we have no actual reference energy consumption data, and that the AC itself is only one variable in the equation, beside other factors such as room size etc. He came up with the idea of looking for projects involving standardized rooms, for example hotels. There, we could install regular equipment in some few reference rooms and then easily monitor the difference to the other rooms with high-end equipment.
I imagine that there could be some other issues arising from that approach, as it requires individual consumption meters for the reference rooms. There just seems to be no simple solution for this.