HI Snuffy,
I have a 3055RL and it is listed the same way. I have an air-conditioner in the bedroom also and it is not a low profile unit. I measured mine hooked to tow vehicle and on level ground, I was 13' 2". I know it must be OK, because I have been under some 13-6 underpasses and have not knocked anything off. This is with my unit on a one ton GMC dually, hitched is set to where the trailer is pretty level when towing.
I'm sure some others will chime in also.
Jim M