Add an additional AC to my Montana 2980

[captain1]

We're thinking of adding an additional AC to our Montana 2980. It is supposed to already be wired for one. Any suggestions as to size, installation, or any other necessary thermostadts, etc. would be appreciated

[BB_TX]

We added a 13.5k low profile to ours years ago. Not ducted. Uses the built in controls. Pretty loud. But we typically only use it to help cool the trailer after a long day of travel in hot weather. Never run it at night. Once the trailer has cooled the rear 15k does a good job of keeping it cool.

[prndl]

I just yesterday completed the installation of a second A/C in the bedroom. Would have been a snap if I used a ceiling plate with the controls on it.
I installed a second thermostat next to the original one on the steps. That was a PITA.
The original vent came out clean. The boxing Montana put in to block off the ceiling was full of gaps so when installed the A/C I reused the original vent inside part to form a tunnel up for the A/C return.
I installed a low profile Carrier 15K unit.

[petersrd]

We had a 13.5k Penguin added to our 3150. No ducting and used the controls and thermostat that came with the unit. As stated, the trailer is prewired for a 13.5 unit.
The built in thermostat only controls the compressor. That means, the three speed fan runs as long as the unit is turned on. It is a little loud, but does a good job of keeping the bedroom cool. We usually do not need to run the bedroom unit at night, as the main 15k unit does a good job.

Hope this helps.

[1retired06]

Added dometics to our 05 and 10 units, bedroom installs, stand alone ( no external thermostats, no ducting) Easy installs thru front vents, (after I got them up on the roof!), wiring already in place.

[hunts800]

Same as BBTX. Ours is not ducted, but has a remote. Does excellent job of cooling the bedroom, but it is fairly loud. Only leave it on all night if in very hot temp, (100 and above) otherwise the main ducted unit will usually keep the bedroom cool at night. I would definitely look for the quietest one you can find, if the db levels are shown in the specifications sheet. Excellent way, however, to cancel out any noisy neighbors!

[CaptnJohn]

My 370br arrived with the 2nd AC. It is on a separate thermostat and is ducted. It is a 13.5 Dometic. Wish it were another 15K like the main unit.

[twindman]

I also had a 2980 and added a 2nd AC. Necessary when on the road in heat. Hard to cool Monty when temps inside are 90 or 95 after traveling all day. That is about the only time I use the 2nd AC, but when you need it, you need it.

[Arizonacouple]

We needed additional cooling in our High Country living room. We bought an 8k Haier portable unit from Walmart. It sits next to our fireplace and is ducted through a side back window. We fashioned a cardboard template to accept the flexible ducting and also a fit into the window. With temperatures in the high 90's it has been a blessing.

Truly, necessity is the mother of invention.