In construction, the R-value is the measurement of a material's capacity to resist heat flow from one side to the other. In simple terms, R-values measure the effectiveness of insulation and a higher number represents more effective insulation.* The R Value through a typical 2x6 wood stud is 6.88. Any wood member causes there to be a transfer of heat and cold from the exterior of a home or a building to the inside of the same space; known as conduction. The only way to stop the transfer of heat or cold from one side of a wall to the other side is to purchase and install thick enough rigid insulation to the entire exterior perimeter of the structure.
The Tstud™ is the same depth as a 2x6 but offers an impressive stated R Value of 18 and has a 99.23% complete thermal break** through the stud. Meaning that there isn't a need for continuous rigid insulation to meet and exceed the 2015 Energy Code in all of the climate zones in North America.
Typically, the maximum R Value of any continuous insulation is only 5 and is ¾” to a maximum of 1” in depth.
The Tstud™ has approximately 2-1/2” of rigid insulation and we are using a stated R Value of 14.25. Add in the R Value of wood at 1.25 per inch, times 3” of wood, and you get a combined wood and foam R Value of 18.
Why we say “stated” R Value: In preliminary testing, our foam tested out at an amazing 8.24 per inch, but this was an “unaged” R Value. Meaning that not all of the gases created in the process of turning liquid foam into a final rigid insulation product, had escaped the foam. It was also at 1.9 pounds per square inch (psi) density. The density in the 8’ Tstuds™ is roughly 2.2 psi; which is less than what is used in the 16’ long Tstuds™. The standard R Value of foam is 6 per inch and we have discounted that value down to 5.7 per inch. It's also impossible to know the depth of the actual foam or to know for sure how deep the wood members are. A 1-1/2” depth of wood can be anywhere from 1-3/8” to as much as 1-5/8”. So, in order to do our best to not overstate the R Value of the Tstud™, we have elected to do our best to understate than to overstate the facts.
Regarding the 99.23% complete thermal break through the Tstud™:
The proprietary truss system that holds the 2 wood members together accounts for .77% of a thermal transfer of heat and/or cold.
The truss is non-metal and is fully encased in foam. Continuous rigid insulation is attached with metal nails and still has up to .5% of conduction through the foam, depending on the diameter of the fastener.
By using the thermally broken Tstud™ Wall Assembly, a reduction of 4-7 points on the HERS numbering system is garnered thus yielding the building an approximate 18% improvement (depending on heating or cooling degree days and the climate zone energy code currently in force) in energy efficiency over standard 2”X 6” wall construction. The Tstud™ will be an excellent LEED (Leadership in Energy and Environmental Design) product.
This increase in the R factor is significant as there is not another solution that acts alone to offer as aggressive of an outcome.
Therefore, with incentives to both builders and consumers being offered by way of rebates through government and utility providers, there is an opportunity to drive change to build with more energy efficient components to meet the new rigorous energy code legislations and net zero effect initiatives.
** Complete thermal break: is an element of low thermal conductivity placed in an assembly to reduce or prevent the flow of thermal energy between conductive materials