Smith Bucklin-United Soybean Board-JEC Wall Technology was jointly developed by the soybean foam industry and recycled cotton insulation producer. Innovative wall insulation configuration, which consists of 1-in. thick layer of sprayed soybean foam and cotton insulation batts, is designed to be used in wood and steel-framed wall assemblies. Walls were constructed and tested in the ORNL hot-box during fall months of 2006.
Description Of Wall
During October and November 2006, wall assembly using Smith Bucklin-United Soybean Board-JEC Wall Technology was constructed and tested in the ORNL guarded hot-box using ASTM C-1363 procedure. During hot-box testing, this wall was insulated with cotton fiber insulation batts and sprayed soybean foam. Conventional 2x4 wood framing with studs installed at 16-in. on center was used. The test wall was constructed in the way to achieve approximately 25% of framing members within the hot-box measure area. According to the 2002 ASHRAE and CEC studies, 25% of framing is representative for residential constructions in the US. For comparison, hot-box test R-value of the similarly constructed conventional 2x4 wood stud wall (with 25% of framing) insulated with R13 fiberglass insulation is R-9.65 h ft 2 F/Btu.
After installation of the wood framing, and ½-in. thick OSB sheathing on the back surface of the wall, approximately 1-in. thick layer of spayed foam was installed in the wall cavities.
Figure 1 shows the wall after installation of the sprayed foam.
Next, in the remaining space of the wall cavities, the cotton insulation batts were installed, as shown on the Figure 2. Since the thickness of the cotton insulation batts was approximately 3-in., they had to be compressed to fit the wall cavity.
Figure 1. Wall cavity after installation of the sprayed soybean foam
Figure 2. Installation of the cotton batt insulation in the wall cavities.
Conventional ½-in. thick gypsum board sheathing was installed to complete the assembly of the test wall. After installation of the cotton batt and foam insulations, exterior, and interior sheathing, the wall was placed in the ORNL hot box.