There is no need to tell you that this has been a very hot summer. I thought this column we wrote for an RV magazine in 2007 might be timely.
Dear Joe and Vicki: We purchased a 33 foot fifth-wheel trailer with three slides last June. It is equipped with 30-amp service and one 15,000 BTU air-conditioner. During a week of 100 degree weather we could not cool the trailer to a comfortable level. The manufacturers of both the trailer and air-conditioning unit said everything was within specifications and there was nothing they could do. Any assistance you can give us would be appreciated.
Joe: I’m sure the RV and air-conditioner manufacturing experts have determined that a 15,000 BTU air-conditioning unit is adequate for your 33-foot trailer with all three of its slides extended. As one who has been there, though, I can understand how your air-conditioning unit might be fighting a losing battle to maintain a comfortable interior temperature when the outside temperature is 100 degrees and your RV is in full sunlight.
Understand that RV air-conditioners are designed to reduce the air temperature by 20 degrees. That means your air conditioner is working okay if the air on the outlet side is 20 degrees cooler than the air on the inlet side. Your air conditioner is doing about as good as can be expected when the outside air temperature is 100 degrees and the interior temperature of your RV is 80 degrees.
I’m sure you have already discovered that the interior of your rig can become an oven when it is parked in full sunlight on a hot day. So shading as much of the RV for as long as possible should be a prime objective when selecting a place to camp.
Obviously, a campground with lots of trees and grass is going to be cooler than an RV park that resembles an asphalt parking lot. If you are really lucky, you will find a tree-shaded campsite. Try to avoid parking on or next to a hot surface. A grassy campsite will radiate less ground heat than a paved site. A concrete patio outside your entry door is nice but it will reflect the heat of the sun against the wall of your RV.
If you can’t find a shady campsite, try to locate one that points the front of your RV towards the south or east (south-east would be perfect). Your large street-side wall will then be on the naturally shady side of your RV during the hotter times of the day, your patio awning can shade the curb-side wall, and one end of the RV will be shaded at least part of the day. By the way, you can increase the shade of your patio awning by adding mesh patio shades that hang from your patio awning.
Vicki: Keep the sun from shining on or through your windows and skylights. Install window awnings and use them. Close the window blinds on the sunny side of the RV. Better yet, place Solar window covers or reflective foil on the interior of windows and motorhome windshields exposed to the sun. Poster board, cut so its dimensions are just a little larger than the skylight, can be stuffed into the skylight opening to block the sun.
Give your air-conditioner a head start. Turn it on early in the day and let it pre-cool the interior of the RV.
Keep the cool air inside and the hot air outside. Close all the windows and doors. Minimize the number of times the entry door is opened.
Use a fan to circulate the cool air. Direct the fan so it blows air from under the air-conditioner towards the area you want cooled the most.
Decrease the air-space the air-conditioner has to cool. Shut the bedroom door and close its air-conditioning vents. If you do close the bedroom door, be sure to open a bedroom window on the shady side of the RV so the bedroom doesn’t get much warmer than the outside temperature.
Avoid cooking with the stove top and oven. Use the microwave (but not the convection) oven. Use the outside grill. Use electric cooking appliances outside. Better yet, and my favorite, eat dinner in an air-conditioned restaurant.
When all else fails… hitch up and move to a cooler climate.
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