Big hole for ventilation

We have been having a bit of a trail with fitting the heat recovery ventilation. The first unit was the wrong length and didn't go all the way through the wall, the replacement was sent in the wrong width. But that is ok because we didn't get the wider one because it was more expensive - so good news. Another plus of the wrong size was that we ended up having to redo the hole in the wall. This was a good thing because the original one was slightly in the wrong place, but we didn't want to redo because it is quite a big job. 

You can see the origional hole (filled in) and the new bigger hole here.

Here is the unit. It was quite unwieldy to bring on the plane.