Like for like

I have been thinking that to help me keep my seed potatoes from sprouting over winter, a fridge might offer a good solution.  So, finding myself at a loose end in a supermarket recently, I was wandering around looking at the fridges.

I was intrigued the other day by a poor energy rating (F) given to a highly efficient light bulb (an LED), so I paid attention to the energy labels on the fridges.   I saw two apparently equal-sized fridges, one rated F, the other rated E.   According to the label, the E one consumed 141 KWh per year, that is more than the F one that consumed only 112.  They both appeared to be the same size.   What is going on?  

Aha!   The E one has a freezer compartment inside at the top, the F one does not.  The fridge compartment is therefore a bit smaller than the F one.  So, apparently, fridges with a freezer bit are assessed differently: they are allowed to consume more electricity and still get a better rating.   Not comparing like with like.

Wandering on, I found a tall fridge with no freezer compartment but a bigger capacity (263 litres instead of 127 litres - twice as much as the F one above.   It consumes 133KWh per year vs 112, that is 18% more.   Energy rating also F.

So a fridge with twice the capacity for only 18% more electricity consumption doesn't appear to be more efficient?  On marche sur la tête.

Beware simple labels.   I ignore "nutri-score" labels for much the same reason.