This morning, it poured rain again. It was a brief dousing, but a powerful one, and it happened in the hours between my 3am move for alternate side parking and before my 6am wakeup call.
The roof the Airstream 19 is crowded with technology. There is an air conditioning unit, a TV antenna that picks up local HD signals, a hookup for a satellite antenna, and a 250-volt solar panel that feeds the two deep-cell batteries boxed behind the propane tanks up front. There are also two very crucial ceiling vents that opened by electric motors. Powerful exhaust fans expel all the hot summer air that builds up inside and draws fresh air in through the doors and windows. For all its cleverness and clean design, the Airstream has one potential flaw: it's hard to push air around on hot days.
And that's why you keep those vents open all the time. The downside? When it rains, water could run inside—lots of it. That's a problem in the forward vent, which opens over the dining/kitchen area. But the real problem is with the aft vent, which is situated more of less right over the bedroom.
If you leave the trailer and a rainstorm starts, you're coming home to a sopping mattress.
That's where the ingenuity of Airstream has found a solve. If you're away and the rain starts, the vents have a sensor that automatically close them, saving you from untold discomfort and the ruination of a long weekend. According to Airstream engineer Mike Goetz, there is a rain sensor on the roof "like a set of fingers, side by side, that when a drop of water hits them, it completes the circuit and causes the vent lid to close."
Beware, fellow Airstream boondockers: This system does not work when the battery is in "store" mode.