They seem to have mixed up horizontal and vertical, and if they did, then my reading is that they're saying the cost of the extra floor space (and the loss of the "shelf" space on top of the fridge) when using a chest fridge makes the economics unfavourable for people in dense urban areas, even with the energy savings.

At least, I'm hoping that's what they meant. If they really meant horizontal and vertical in the way they used it then I've got no idea either.

I didn't get it until reading your comment, but I think perhaps they meant 'vertical' as in 'it opens vertically' (chest freezer)—i.e. they didn't mix them up exactly, just used them differently than we expected.

Yeah, I understand your first sentence, but the last part of their comment was

"Plus, a horizontal fridge is just… convenient. You can’t even put things on top of a vertical fridge."

Don't they mean a horizontal fridge is a chest fridge? Which would make it sound like they want their whole comment to be in support of a chest fridge? Which is why none of it makes any sense to me.