I also ponder such things ...The other thing to consider is, leaving your bedding inside when closed, this increase height.
That's precisely what I was thinking. I figure that I currently do ground camping with a tent, sleeping pad and sleeping bag. Why can't I do it the same way using a rooftop tent? If the drag penalty for a roof rack alone is an 8%-12% decrease in MPG, the drag penalty for an extra 3 or 4 inches of stowed tent height must be huge. I'd be happy to roll up the bags and store them in the back of the truck if I could have a 4-inch high (stowed) rooftop tent (plus the ladder).
BTW--I just revisited your DIY trailer tent post. Wow--A lot has happened in that thread since I last had a look. 13 pages now. I've gotta catch up!
As noted, Aluminum is great at conducting heat / cold, this can cause condensation between the floor and mattress in cold weather
Well...There are sooo many factors that go into calculating condensation rate. I figure that if I have a piece of closed-cell foam padding bonded to the aluminum deck, I gain a couple of advantages in the fight against condensation: 1) The closed-cell foam padding is airtight and waterproof, creating a moisture barrier between the inside air and the aluminum deck; 2) It provides an insulative barrier between the warm, high-moisture air inside the tent and the cold aluminum decking. This should, hopefully, keep the air that's in contact with the foam padding above its saturation temperature, which is the key to the whole effort.
Ahhh, the age-old quest, the perfect tent fabric. I'm still working on finding it.
Everybody is and has been for ages! I don't believe that Gore-tex will solve the condensation issue, by any means. There just isn't enough outflow of moisture and water vapor will still condense as it passes through the cold gore-tex fibers.
I'm trying to avoid using a rain fly. The theory with the rain fly is that the tent fabric itself easily conducts moisture through it. That means that it lets moisture out easily but it also lets moisture (rain) in easily. If precipitation is anticipated, one uses the waterproof rain fly to shelter the tent from the rain and to provide a surface for the escaping moisture from the tent to condense on and dissipate by rolling down to, and off, the lower edges. Even still, condensation forms on the inside of this style setup.
One must overcome the condensation problem by controlling the causal factors:
1)
Relatively colder tent surfaces; Insulating the interior of the tent from the cold exterior so that the interior surfaces remain above the saturation temperature of the air inside the tent.
2)
Moisture-laden interior air; Either have everyone in the tent stop breathing or find a way to reduce interior humidity to a negligible level.
3)
Relatively warmer interior air; If the interior air is thoroughly vented before it comes in contact with the colder tent surfaces, condensation should be minimized or eliminated. This is accomplished through aggressive ventilation, which also means that the air inside the tent will be at, or almost at, the outside air temperature.
It's a tough code to crack; Everything is a compromise. It's a difficult problem to address while keeping everything simple.
