Summer heat

Depends on where you are, ambient temperatures, and how much sunlight. Also depends on what you mean by "cool."

My 2004 Itasca Spirit, with similar insulation and window area to the Sightseer of the same era, will reach 100 F inside in full sunlight within two hours on a 80 F day. My single 15K BTU/hour A/C will bring it down into the 80s within an hour, but it is faster to open the windows and draw in that "cool" 80 F air before starting the A/C.

In full sun on 100+ days, I can expect to cool down to the mid 80s in sunlight, somewhat cooler in the shade. At night, if it is still 100 F, I can get the temperatures down into the 60s if I want to, but I don't want to. I don't cool my home much lower than 80 F when temperatures are in the 90s or 100s.

WE have a 36' and only use 1 air at a time. Only once this summer did we turn on both units and that was when it was 95 with heat index of 112, so very humid. Our 1 unit cycles on & off except if it's sitting in direct sun with no shade.

Keep both AC unit fans on "high" especially in humid weather. Prevents them from freezing and shutting down. We had a 31' Sightseer with only one AC and it wasn't enough. We have a 33' Country Coach with 2 slides and 2 AC's keep it plenty cool. We do put the quilted aluminized insulation in the windshield area. You can buy a roll at Lowe's or Home Depot.

There are two units and they are duct-ed. I walked around the MH with the TV at a healthy volume and couldn't hear anything but our drier running. So I gather the insulation is pretty good.

Chris, when we lived on the boat we ranged from Charleston to Savannah. It's gonna be a lot cheaper to go a hundred miles in the Winnie than it was in the Chris. I'm sure we've passed by you a few times.

Thanks guys

I did fine with one 13500 in the Jayco living in it here for a few summers before we bought the house and up until I sold it.
I kept it cool and the unit cycled on and off throughout the day.

If you have two you should be fine. I did keep the blinds shut during the heat of the day which was a big help.

With the humidity here the key is keep the door closed, before it can cool it has to draw the moisture out. I was less than 15 miles to the open ocean both at the campground and here at the house. At the campground I was under some big live oaks that provided shade, at the house here it was in the open with some shading later in the afternoon, never a problem staying cool.

We did use it for a few years at the house for guests to stay in until we decided to sell it and get something smaller that we have still yet to find.
Never a problem keeping it cool here either.

Look for shade. In the broiling sun RV can get hot. If you have duct work for your air it will do some better.