How can I disambiguate "shorter"?
To compare a cuboid in all three dimensions, you can use these three pairs
- taller/shorter
- wider/narrower
- deeper/shallower
So you could write I prefer this closet for hanging clothes because, even though it is not as tall or as wide as the other, its greater depth gives each item more space.
Items are often referred to with various dimensions: length, width, height and depth.
Shorter can apply to any of these, so the term is inherently ambiguous.
You can sometimes avoid the ambiguity by specifying a combination of dimensions (as Fortiter said) so that it becomes clear by process-of-elimination which dimension "shorter" refers to. But even that requires some mental parsing by the reader.
The only way I can think of to be absolutely unambiguous is to spell it out:
The length is 1" shorter...
The height is 1" shorter...