The SIP polyurethane panels used for energy efficiency and speed of construction of SIP structures is usually the most important quality of SIPs for our developers, contractors, homeowner commercial and industrial clients and the architects and designers they employ.
Long-term benefits of using Greenix SIPs polyurethane panels provide up to 60% in energy saving when compared to stick framing, even when stick frame structures are designed and framed with energy efficiency in mind the extra cost to do so elevates the cost above and beyond what our Greenix SIPs roof panels or wall panels will cost. A home, commercial or industrial structure designed to maximize efficiency using the polyurethane panel SIP System consistently performs 50% to 70% better than the Model Energy Code. Savings from lower energy consumption to heat and cool the home continue for the entire life the home and are especially great in areas with extreme weather. Please also consider your quality of windows and doors when building any structure. The SIP energy efficiency is beneficial and will increase the resale value of the home more every year.
There are two primary ways polyurethane panels provide this improved efficiency:
1) higher effective thermal resistance, and 2) reduced air leakage.
1) Greenix Polyurethane Panels SIPs provide almost 2 times higher R-values than EPS or XPS foams, plus and will always perform than stick framed (and insulated) walls and roofs of equal thickness. The R-value of a assembly is a measurement of its ability to resist heat flow. Higher R-values represent higher resistance to heat transfer, which translates to reduced energy consumption for heating and cooling.
2) Greenix Polyurethane Panels SIP structures are not more energy efficient simply because of the higher insulating values of the panels, but our panels also reduce more air leakage, a major source of energy loss in most buildings. With stick framing, and eps type foams it is much more difficult to create a consistent tight seal throughout the home or building, which results in air leakage. Remember the greater the air leakage, more severe the reduction in energy efficiency.
For example, a 2×6″ wall with R-20 batt insulation yields an effective thermal resistance of R-16.8. A six-inch Greenix SIP System wall (which actually measures 6 1/2 “) has an effective thermal resistance of R-40, which is more than double the R-value stick frame or a EPS panel of 10 1/8 inches thick. Considering roofs, a 2×12” joist roof with R-35 batt insulation has an effective value of R-31.9. Compared with the slimmer 6 (six) inch Greenix SIP System roof (which actually measures 6.5 inches “) that has an effective thermal resistance value of R-40, the thinner SIP roof provides 18% greater insulating value than the joist roof insulating system..
It has become a common practice in many areas to test homes and buildings for energy efficiency by measuring air tightness through blower door tests. Properly installed Greenix polyurethane panels provide a very tight “closed cavity” that consistently performs well during and after these tests. In fact, ORNL evaluations of a SIP test room revealed the SIP room to be fourteen time more airtight than an equivalent room with 2×6 construction, sheathing, insulation, and drywall. For this reason, the EPA does not require a blower door test for homes built with SIP walls and a SIP roof.
EPA National Director for Energy Star Homes Sam Rashkin estimated the additional costs of materials necessary for a stick built home to meet the new Energy Star Standards between $600 and $1,200 for materials only (prior to 2006). If obtaining an Energy Star rating, there are also additional savings if the entire home envelope is built with properly installed SIPs (exterior walls and roof) because a blower door test or a duct blaster need will not need to be performed, reducing overall rating costs.
The most energy efficient buildings and homes can be accomplished by integrating both the structural insulated panels used on all exterior walls and roof with insulated concrete forms (ICFs) used in floor and ground-level components. Incorporating other energy efficient products, especially doors and windows, should produce substantial long-term savings through reduced energy consumption.