Roof Top Air Conditioning

[Lenna F]

We have just about finished all of the updates to our Trillium 1300. We resealed all of the windows, new flooring, curtains, interior lights, cupboard doors, closet shelves, bike hitch on back, etc. We are so excited that we can't wait for next summer to come.
Our question is, has anyone installed air on the roof? We have seen pictures in the old Trillium brochures with air on the roof but is it possible for a DIYer to do? If yes, what size, how to install, power hook up? Any advice and pictures would be appreciated. Maybe the roof isn't strong enough but we didn't want to give up closet space or the area above the sink.
Thanks.

[Chester Taje]

Its my understanding that if unit did not come with roof A/C, then you cannot do it as roof has not been specially reinforced for A/C.