All of the savings, ratings and comparisons are based on like-for-like products, which in general terms is the size or capacity of a product. Examples of classifications:
Dishwashers. Classified by size: compact, slimline or full size.
Freezers. Classified by type and capacity: chest 100-199 litre, chest 200-299 litre, undercounter, upright 100-199 litre, upright 200-299 litre, etc.
Fridge freezers. Classified by type and capacity: 50/50 100-199 litre, 50/50 200-299 litre, american 500-599 litre, american 600-699 litre, etc.
Fridges. Classified by type and capacity: larder undercounter, larder 100-199 litre, larder 200-299 litre, ice-box undercounter, ice-box 100-199 litre, ice-box 200-299 litre, etc.
Tumble dryers. Classified by capacity: 7 kg, 8 kg, 9 kg, 10 kg, etc.
Washer dryers. Classified by wash capacity: 7 kg, 8 kg, 9 kg, 10 kg, etc.
Washing machines. Classified by capacity: 7 kg, 8 kg, 9 kg, 10 kg, etc.
It’s essential to compare like-for-like as, for example, it does not make sense to compare the running costs of a 6 kg washer with a 10 kg washer, as the larger capacity washer is likely to use more energy.
For refrigeration, as there are no standard sizes, products are sub-categorised by type and capacity for comparison. For example, it doesn’t make sense to compare a larder fridge with a model that has an ice-box, because freezers use much more energy. Similarly it doesn’t make sense to compare a 50/50 split freezer with a 70/30 split, as the model with 50% freezer will use a lot more energy than the one with 30% freezer.