Suitability of Single Wall Shelter or Tarp

re question 2: David Olsen’s photo in THIS THREAD shows a pitch that might meet your needs.

There is condensation on:

1) the outside of your tent.

2) the inside of your tent.

There is water vapor in the air outside of your tent and there could be a different concentration of water vapor on the inside of your tent, such as from exhaling water vapor from your moist lungs.

To avoid the condensation of water vapor on the outside of your tent, you would not like the tent wall to reach a temperature which is less than the dewpoint of the outside air. Heat from your bodies or a hypothetical safe heater inside the tent is one way to keep the tent wall temperature from dropping to the dewpoint.

It is also possible to think about not letting the tent wall get too cold, by radiation cooling — the tent wall radiating heat to the cold empty night sky on a clear night. The meteorology texts discuss this nightime radiation as one reason why the grass gets wet so easily in evening/nightime conditions of temperature dipping near the dewpoint.

Pitching your tent under a tree will cut down your radiation loss to the cold nightime sky.

One campground I bicycle camp often is in a steep valley overlooking the Mississippi River. Almost every morning, the picnic table is sopping wet. My tent used to be always pitched for a clear view of the night and morning sky, and it too would get sopping wet. After reading the meteorology book, I would pitch the tent well under a tree and without a clear view of the night sky. Usually, very little to no condensation on the outside of the tent.

Leaving the doors and vents as open as possible gives pretty condensation free tent interiors too. The inside of the tent is warmed somewhat. Countering this is that I am a source of water vapor all night long.

According to Jardine, the openness of the tarp gives much less condensation, perhaps eliminating all of it on the inside.

I do know that one of the worst condensation nights I had in a single wall tarp tent was one hot night in a river bottom growing corn where you could see wisps of fog drifting over the corn fields, and there was no tree in sight that would give good sky cover. Another was sleeping in a valley next to the creek away from any tree cover, and I had pitched the open end of the shelter facing uphill (the breeze was uphill in the day when I pitched it, but downhill after the onset of nighttime cooling).

The tree doesn't stop "dew falling" as it might slow down "rain falling". The tree slows down the radiative cooling.

Jim

The campsite won't have any appreciable tree cover. The trees in that area are all deciduous and leafless right now.

Also, we'll be required to pitch the tent or tarp in a cleared area (ie: State forest tent pads). Some sites are ringed with trees, but the trees don't overhang the tent pads even in the summer. Also, some of the tent pads are hardpacked dirt that used to have some gravel and some are grass.

I'm planning on pitching the tent / tarp on the grass when possible. I assume the grass will provide a little bit more water vapor at night, but the bare ground is much less comfortable.

It's tough to predict local conditions from a forecast (low spots, body heat, hunmid breath, pitch, moisture in ground, surrounding trees, etc.). However, a little dew probably won't hurt the loft of your daughter's bag for one night out, especially if it's synthetic. Plenty of room for a father daughter under a 8×10 tarp. Use the stoprm pitch…it provides protection, an open front to experience nature more closely, while retaining enough of the enclosed security that a child might enjoy. You can always lift your side a bit and use the lifters to get more headroom.

It might even be fun for her to wake up with dew around, and draw faces on the dewdrops.