Maybe I'm being overly cynical here, or missing something, but from a purely scientific-principle basis, I'd be asking a lot of questions about how effective it was as an air-conditioner (cooling) without a unit on the outside of the building to dissipate the heat - if it was as easy as blowing the heat out through a hole in the wall, it's hard to fathom why every other type of AC unit uses a unit outside the property.
And if the cooling isn't effective, then it's really just a very expensive electric heater which can be had for as little as
£50..