Technical Report. Estimated Savings for Application of JP s Foam Cladding System on an Un-insulated Concrete Slab Wall.

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1 NVLAP Lab Code Technical Report Estimated Savings for Application of JP s Foam Cladding System on an Un-insulated Concrete Slab Wall Prepared For: JEP Management, LLC Attention: Mr. John Propst 3219 East Camelback Road #524 Phoenix, AZ R & D Services, Inc. P.O. Box 2400 Cookeville, Tennessee Report: RD13388 David W. Yarbrough, PhD, PE June 7, 2013 The test results in this report apply only to the specimens tested. The tests conform to the respective test methods except for the report requirements. The report includes summary data but a full complement of data is available upon request. This report shall not be reproduced, except in full, without written approval of R & D Services, Inc. This report must not be used by the Client to claim product endorsement by R & D Services, Inc., NVLAP, NIST or any other agency of the U.S. Government.

2 Estimated Savings for Application of JP s Foam Cladding System on an Un-insulated Concrete Slab Wall Introduction Estimates have been made for savings in heating and cooling costs due to the application of a foam cladding system, JP s Foam Cladding System, to un-insulated concrete slab walls in seven cities. The concrete walls were taken to be 6.5 inches in thickness with concrete density lb/ft 3. Application of the foam cladding system results in a significant increase in the air-to-air thermal resistance. Estimates of the savings have been made with HDD/CDD data from Climatography of the United States No. 81 Supplement no.2 for two cases. The first case does not include a benefit from the massive wall structure (no mass effect). The second estimate was made with a dynamic benefit of massive system (DBMS) value of 3. The DBMS of 3 effectively multiplies the thermal resistance of the concrete slab by 3. Percentage Savings with Four Foam Thicknesses Estimates of energy savings have been made for thicknesses of polystyrene foam in the cladding systems up to 5.0 inches. The thermal resistivity of the foam (R-value per inch of thickness) was taken to be 3.8 ft 2 hr F/Btu in all cases. The presence of a metallic supporting frame was not included in these calculations. The objective is to show the small savings to be anticipated as foam thickness is increased from 3.0 to 5.0 inches. Figure 1 shows the estimated percent reduction in energy use without accounting for mass effect. Figure 2 shows the estimated percent reduction in energy use with DBMS equal three, an upper bound on anticipated DBMS values. Comparison of the results in Figures 1 and 2 shows that 80% or more of the estimated savings are realized with three inches of foam. The magnitudes of the savings between the two cases are different as will be shown in the following section. 2

3 Figure 1. Estimated Savings without Mass Effect Figure 2. Estimated Savings with Mass Effect (DBMS=3) 3

4 Estimated Annual Savings for JP s Foam Cladding System Tables 1 and 2 contain estimated savings resulting from addition of JP s foam cladding system to a 6.5-inch thick concrete slab wall. The savings are $/yr for 100 ft 2 of wall. The input properties for the calculation are R*=0.1 ft 2 hr F/Btu in. for concrete and R*=3.8 ft 2 hr F/Btu in. for the polystyrene foam insulation. The presence of a metallic support member has been included. The sum of the interior and exterior air film resistances of 0.93 has been included. The exterior finish has radiative properties that are different from those of concrete especially in the case of solar reflectance. The solar reflectance has not been included in the estimates. The conversion from thermal savings to dollar savings is based on an air conditioner COP of 3 and a furnace efficiency of The outputs shown in Tables 1 and 2 can be quickly adjusted for different equipment efficiencies. Similarly, the cost of heating was taken to be $10 per million Btu (heating) and 0.15 $ per kwh (cooling). This assumes that heating is done with a fossil fuel. Savings are shown for each of the seven cities listed for four foam thicknesses. The progression of savings in the tables is like that shown in Figures 1 and 2. The total savings in Tables 1 and 2 are dollars per year for 100 ft 2 of wall. 4

5 Table 1. Estimated Annual Saving for Seven Cities (no mass effect) 5

6 Table 2. Estimated Savings for Seven Cities with Mass Effect (DBMS = 3) Summary The results in Table 1 and 2 provide a range of anticipated savings from addition of the foam cladding system to an un-insulated concrete wall. The range is broad because of the large DBMS value chosen. DBMS of three is on the high end of expected values. The expected DBMS value varies with location. David W. Yarbrough, PhD, PE June 2,