Here is a quote from another threard on insulation. http://www.tnttt.com/viewtopic.php?f=21&t=26598&start=15
halfdome, Danny wrote:My first teardrop was totally insulated and once we had condensation on the walls because the roof vent was closed (heavy rain) but the windows were open. The second teardrop is only insulated on the roof and galley hatch. I haven't yet had condensation on the walls or ceiling but I always open a window and crack the roof vent. Both teardrops are identical in size and shape. This suggests to me that proper ventilation is the key to preventing condensation. Insulated walls are quieter and somewhat warmer/cooler than non insulated. Is insulation worth the extra pounds? Only you can decide.Danny
Danny has built 4 teardrops now, all have been fairly close in design and size. He fully insulated his first build, but has not insulated the walls on the last 3 builds. He does state that insulated walls are quiter and somewhat warmer/cooler than non insulated, but to prevent condensation you need good ventilation. By the way good ventilation is also needed to breath, which is where the moisture for the condensation is coming from.
Dan