I have done a basic search for an explanation of the criteria for the A,B,C... rating system on anything (there are different subjects: domestic appliances, houses, cars) but have got no further than the idiot's lesson that a Green A label means better than a Red H label (even on a site that claims to answer all your questions on the matter). What I would like is to know the different thresholds between the letters so that I know what the labels actually mean, rather than the opaque situation whereby nothing is very clear except the letter and colour. Hopefully this is not too much to ask although there is a widespread reluctance regarding clarity in packaging ("large box", "medium size", etc. on things without giving any dimensions or weights) and maybe it's the same with this one. Does anyone know a source for such information, particularly on electrical items ?
they are mostly based on at least two things, for example with fridges it's based on the size of the fridge compartment against the amount of energy used, for light bulbs it's the amount of light they produce and the wattage they use.