installing 2nd A/C unit

I had a Dometic low profile 13.5k installed on my Montana 2 yrs ago. Seems it was about $1,100 installed at Camping World. I had no desire to try to get that thing up there my self.
Be aware that they come as stand alone or ducted models. If your trailer is set up for ducted bedroom AC it can blow air out the same ducts as the rear AC. And can be controlled by the dual zone thermostat, if you have that.
Otherwise it just blows air into the bedroom.
I think the ducted model is a little higher costs.

I've seen youtube vids of two people using an extension ladder and rope to drag it up the rungs to the top. It didn't look too hard, just cumbersome.
Mike

I installed mine and it wasn't prewired for a second one. It's not too bad if you have access to a forklift or something that will lift it to the roof for you. I've seen new units run about $6-800 depending on model.

The hardest part is getting the 90# unit on the roof. The rest is very straight forward.

Had 2nd added to my 3400RL-just a tad over $1200.That equates to just a little over 2 hours labor,the rest the cost of a Dometic unit.Works great.I do not know how I would have gotten the thing on the roof anyway.besides I should not be up there anyway.