30 ft- one roof air sufficient?

Parked in the shade it will most likely be sufficient, in full sun maybe not.

Depending on where you go with it it may do OK or it may struggle. Mine has a hard time in direct sun in 100deg weather. Now if I parked it under a tree in he same type of temps, then it works just fine and will even cycle on/off.

If you camp where there are a lot of trees you'll be fine. If you camp in the desert, you won't be happy!

You will be light on cooling for my taste. I had a 36' with two that could have used more cooling sometimes. Unfortunately smaller coach's also tend to be insulated not so great.

The answer is; it depends. Ours only has one rooftop air. It's a 15k unit. "usually" it's enough. Camped it's not really an issue. Once a few years ago we were at VA beach and daytime temps crept up to 100 and we were in full sun. It would not keep up that day, but as the day waned it cooled it back down. Travelling in those temps is also another story. You add road heat, engine and transmission heat and in 90+ degrees it won't keep up. I would prefer 2 rooftop airs and if this is a tipping point in your decision go with a coach that has two. It wasn't that critical for us and hasn't been a big deal, and the coach we wanted only had one so that's what we got. We are happy, but if you plan on travelling often in 90+ temps it may not work for you. If you are a weekender with small trips it will be fine 95% of the time. It will never be an issue when the sun goes down which is when we spend the majority of the time in our coach. The rest of the time we are out doing stuff and don't keep pets in the rv, so frankly we don't care that much. But in full sun on a hot day or travelling in a hot day, no it won't keep up. It's up to you to determine if you will be in those conditions and how often.

It depends on where you're at. In Texas it won't be enough once the temps are in the mid 90s and humidity is at 75%. We have a 40' with two air conditioners and have seriously considering adding a third AC. We have one original 13.5K and the other has been replaced by a 15K unit. One AC in a unit that size will be a challenge anywhere from Georgia across to New Mexico.

NO, in temps above 90 degrees, 1 AC especially a 13.5k will NOT cool that RV comfortably, even if ducted. If NOT ducted, then hell no. When people ask this type question, go to the RV on a 90 plus day. Stay in the RV for a few hours after 2pm and go in and out a few times. THAT will answer your question. Doug

How is the ducting set up and can you close off the bedroom during the day?

Ours is a 28' 5th wheel so not too different in size.
- In temps below the upper 80's, we just run it using the ducts.
- By the time we hit the 90's, we close off the bedroom and shift the ducts so it blows into the main living area and that keeps it cool up to the low 100's.

Had a 31 ft with 30 amp so could only run one air at a time. Did OK in Texas heat but it also did not have slides.

I owned a 31 footer many years ago and it did just great. Had trouble with it cooling when I was in the Southwest in July in 100* + weather. Good Luck and enjoy your new coach.

We have a 31' Class A with one air conditioner and it does fine for us. I think it depends on how it's vented. We've got vents in the bedroom, so it keeps things plenty cool. Using a fan if you feel like the air isn't getting moved around enough would help.

If the trip to look at the rig isn't going to break the bank, I'd go look at it. Heck, if the rig's in Arizona, you'll know pretty quick how it does!

Good luck!