Transcend Tiny Homes -thermal bridge discussion
Why are composite walls better? Normal walls bleed energy.
A typical wall made up of studs has an energy bridge to the outside of the wall that "bleeds" heat or cool. The greater the difference in temperature between the inside of the wall and the outside, the greater the transfer of energy. Normal insulation methods cannot solve this issue.
Heat transfers through objects like wall studs. It is called a thermal bridge. A normal stud insulates with a value of R2.
If you were to install R13 insulation in between the studs, that fills the voids in the wall. But, air still moves around inside the wall, and the insulation loses effectiveness over time.
Studies are now revealing that a wall like this drops down to an R7 when you average the voids, the studs, and the electrical outlets. That is a 50% decrease in your insulation value. Visually speaking, thermal bridging and air leakage is equivalent to leaving one window open in your house at all times, day and night. This is not good!
Composite walls retain energy.
A composite skin wall is a whole different animal. First, it has to be engineered to be able to support all the loads and stresses of a home, especially one that moves down the road. The bulk of the wall is extruded polystyrene foam. This foam is then laminated under pressure with 2 skins made up of phenolic resin panels. This makes a composite panel that is very strong, very light, and very energy efficient. The standard measures of R values don't apply well here because R value standards were set up before this type of wall was invented.
There are no 'thermal bridges' here. Hence, there is no air flow through the wall internally from heat differentials from the inside to the outside.
There are added benefits. The joints fit together so tightly that air leakage just about disappears adding to the efficiency. Without the weight of wood studs, the foam panels are very lightweight.
We take it all a step further and epoxy resin the joints to ensuring not only a perfect fit, but also prevents any chance of air leakage.
As the tiny home is assembled, all thermal bridging has to be minimized if not eliminated by design.
When we talk about the future of home building, removing the thermal bridge obstacle is a big part of it.