Monodoor Fridge

Used to be a 'fridge had one door which you opened to rifle around for beer or lunchmeat, then you'd open an internal freezer door to look for ice cubes. For some reason this changed to the standard door-for-each-compartment design.

So, change it back.

The Monodoor Fridge has one (1) external door, which holds all the insulation and hermetic sealing, sporting an upper and lower handle, and two (2) inner doors which are vaguely airtight, carry the regular thin shelves, etc. and have no handles.

Pull the upper handle on the outer door and it and <drumroll> the inner upper door opens, exposing the freezer. You can probably guess what happens if the lower handle is pulled, instead.

Long story short, there's less coolth loss all-round since there's only the one thermal door's seal perimeter.