I’ve done it several ways. Hardest was carrying it up on my shoulder. Too old for that now. Second-hardest was sliding it up ladder jammed into open truck tailgate and to a roof corner (needed help on ground). Third was two men on two ladders.
In all of these the ladders need to be tied off. A 15k A/C is 105# ship weight. The weight is not ever the problem, it’s the balance. (Vantage point never exists).
Have seen an RV tech tie off a Little Giant and use an ATV winch with a tackle block to lower/raise along vertical ladder atop a tall Moho. Remote controls. Set up and take down was tedious. Rope nest around ship box was tedious to assemble.
Hired an RV tech who had two men use two ladders just alike and a cross piece “clamped” to both at both ends. It cleared the roof by several feet then they cranked the unit up/down between them with a Manual boat winch (went quick; screw electric).. That crossbar high enough they were on ladders whole time and could swing on/off the roof the old/new units. Third man (boss) was on roof
Some fab skill, but he’s doing it regularly. This was steadiest I’ve seen (given no tractor or other lifting equipment). The cross bar and DOUBLE LADDER FOOTING replicated each other. (Ladders free for normal use once attachments dismounted).
AC unit stood up momentarily to travel vertically. That’s where two men made things easy: the partial flip onto the roof (packing case still closed). Didn’t need third man.
The attachments just traveled on vans roof rack with ladders.
