[Motor31]

I grew up worked and lived in Tucson for over 50 years. I also had the misfortune to stay 2 summers in Tucson in our MS due to medical issues in the last 5 years.

If you think the insulation is all that great in a MS, enjoy the fantasy and I hope it keeps you cooler by believing that. DRV depends on roll fiberglass insulation. That style of insulation always drops due to gravity when in a vertical installation. Shake the unit by traveling down the road and it will settle faster and farther than in a fixed location.

Every window in the unit cuts the insulation factor of the wall dramatically. Dual pane windows are better than single pane but that is like saying a half of cup of water to drink in the desert each day is better than a quarter cup. It is better but it is in no way good enough. The dual pane windows do nothing to stop radiant heat from the sun. It shines through and heats the interior. Shade is the only way to stop that radiant heat. If the sun shines on the window the heat will transfer. If you have a window shade over each window not covered by an awning that will help a lot. Putting the trailer in shade will be a great help in staying cool. Keeping the sun off of it keeps the unit from heating up a lot. That will help the AC units quite a bit.

The big awnings help keep the walls shaded and you should have 2, not just the one that is the normal installation. Watch out for storms though as they will remove the awnings from the trailer very violently. Never ever count on the automatic wind sensor to work properly and safeguard the awning. In a thunderstorm the winds will gust up to over 50 miles per hour faster than the sensor, if it works at all, can respond. My sensor failed and would wind the awning up in a no wind condition just because the temperature got to 90 degrees.

Two AC's are absolutely mandatory for any degree of comfort in the desert. When one of ours failed, the coolest the trailer would get during the afternoon would be 90 degrees in July. When both were working the trailer would cool down to 30 degrees lower than outside temperature. That means 80 inside when it was 110 outside. In Phoenix it is actually about 5 to 8 degrees HOTTER than Tucson. When the temperature in Phoenix gets to 120 degrees, and it does several times, it will be a nice cool 90 inside your rig.

Swamp coolers are great but you MUST have flow through ventilation for them to work. They do not recirculate air like an AC unit. They take outside air, run it through water saturated pads to cool it by evaporation and shove it through the structure. You have to have enough outflow to match the inflow or the air sits. They use a tremendous amount of water, as much as 60+ gallons a day for a small one. They do not work when it is humid outside like during the monsoon season or in Phoenix itself due to the canals all around the place. That's why those in phoenix converted to AC when the cost got low enough to do so in their stick houses. Very few folks in that city would consider a swamp cooler for a stick house they were building or buying today. Even in Tucson where it's drier they are losing popularity, I know as I have had both in two of my houses and after a couple years didn't bother with the swamp cooler. My last house only had AC when I had it built.

Keep in mind that the trailer runs on 50 amps. If everyone in the park is using a lot of electricity, and they are in the summer, voltage may become an issue if it is an older park. The power situation can also be an issue for the grid there and there have been some brown outs in the past. Since a bunch of folks bailed out of Phoenix after the economy tanked that may have gotten better but in Tucson they still call for folks to conserve power during peak times (afternoon) in the summertime. Trying to run the 2 AC's and a window unit will trip the breaker very quickly. Breakers also lose some ability to maintain full power in hot conditions as they trip from heat build up. Trying to keep breakers cool when the sun is heating the breaker box to over 130 degrees is difficult.