I've been looking into this a bit more and am leaning towards the split variety. Not sure what you mean about a massive box in the wall - the one I'm looking at only needs a single hole that's definitely smaller than the ones on the inside only one you posted. Downside is an ugly thing on the outside obviously, but can always put it on the back out of sight. Also needs to be installed by a professional. Upside is a much smaller unit on the inside which really appeals to me. Also cheaper
I've been looking into this a bit more and am leaning towards the split variety. Not sure what you mean about a massive box in the wall - the one I'm looking at only needs a single hole that's definitely smaller than the ones on the inside only one you posted. Downside is an ugly thing on the outside obviously, but can always put it on the back out of sight. Also needs to be installed by a professional. Upside is a much smaller unit on the inside which really appeals to me. Also cheaper
For reference: https://www.appliancesdirect.co.uk/p/iqool12plus/electriq-iqool12plus-air-conditioner-air-conditioner