Document 3Jnepq143OG3rgkkNyXGDYoVx

r"~3' 31- 3004- DiFGccdrich Fabricated Polymers Division DEPT. NAME/ Susan L. Goldstein LOCATION WHB-3 AUTHOR(S) Mary B Lattimer Brecksville COPY APPROVAL AUTHORITY: ;(/: o BFG TECHNICAL DOCUMENT INTERNAL BFG USE ONLY OEPT. 1911 NUMBER DATE 11/12/85 PROJECT NUMBER REPORT TYPE 6IF06F5 IOC au. WORTS MUST INCUlOC. SUSJgCT, AIMRgNCU. K1Y WORM. SACXaAOUNO. RAOORAM ORCNMO MUST tNCLUOt RROCSDURt. COST OCTAlt AGt RAOGAAM CL03URI MUST inCUJOI: CONCLUSIONS. RECOMMCNDATIONS. OSSCRWATIONS. DATA summary. COSTS IAwoven VS. ACTUAL!. SUBJECT: THERMAL PROPERTIES OF WALLCOVERINGS I have attached an article that describes a university study on the thermal properties of wallcoverings. The study included various vinyl coated and fabric wallcoverings. The results of the study included a calculated value for the specific thermal conductivity coefficient (K) of each sample. The article related these "K" values to the thermal insulation properties of the wallcoverings. In particular, the greatest amount of insulation was provided by wallcoverings which had the lowest K values. While the article did not correlate the measured k values to actual energy savings, it did reference a report that stated most homes lose 17% of their heat through the walls. The inference was that some or all of the heat loss could be reduced through the use of insulative wallcoverings. Based on the types of fabric wallcovering samples that we are now receiving, I believe we could determine and assign K values to these materials. I'd appreciate your comments on the marketing value of this subject. cc: E.L. Gill E.A. Huettel J. Mason R.S. Varga DISTRIBUTION: Mary B. Lattimer The BFGoodrich Co. DEC 1 1235 Brecksviile R&O Files This oocumerw eomamt tonhoontisl isformsoon an* is lor imomai 6PQ use or* "wood io-tao" bos* Store n mojo ares wnon not m wso Ooaroy wtm no longor noaoao. Tifto9seo: BFG08378 November 1982 703 Thermal Properties of Wall Covering Materials Barbara M. Reagan and Ludwig Villasi Department of Clothing. Textiles anti Interior Design. Kansas Agricultural Experiment Station. Kansas State University. Manhattan. Kansas 66506. U.S.A. ABSTRACT A major source of heat loss in homes is through walls. Increased insulation on interior walls may reduce energy consumption for heating and cooling. This study evaluated the thermal transmittance characteristics of 15 wall coverings that differed in weight, thickness, density, fiber content, and construction characteristics. A guarded hot/cold plate was used to measure the thermal conductivity of the fabrics. Significant differences in thermal transmittance were found among some of the wall coverings evaluated. Introduction Since the dawn of civilization, man has used var ious means for achieving warmth, fulfilling a basic need of protecting the body against harsh elements. Methods to improve housing throughout the ages in terms of aesthetics as well as thermal comfort include the use of a variety of wail covers on interior walls. Primitive man achieved added warmth by hanging animal skins, while centuries later, fine tapestries kept drafts to tolerable levels in medieval buildings. It was much later, however, that wallpaper achieved a uni versal acceptance, when it was considered aestheti cally pleasing, economical, and functional (i.e.. pro vided acoustical insulation and reduced maintenance on interior surfaces) [4, 17]. Today, there is an in creasing demand for textile products to cover interior walls in residential and commercial buildings as a replacement for wallpaper [15, 16]. Many kinds of fabric and paper constructions made from both natural and man-made fibers are used as wall coverings, ranging from flocked and printed papers, grasspapers. simulated suedes, and jute fabrics laminated to a paper base, to thicker fab ric constructions similar to those used as floor cov ering materials [3, 13]. Present concerns for energy conservation have compelled specifiers and users to shift concerns from price, design, etc., to thermal in sulation and other functional qualities when selecting wall covering materials. Because of the price and ap plication difficulties encountered when traditional floor coverings were applied to interior walls, Heavier textile products with increased insulation are now being specifically designed as wall coverings. Several studies have investigated the thermal insulative properties of carpeting [5, 6, 7, II], The Car pet and Rug Institute stated that carpets and rugs may have potential for reducing 'energy consumption for heating and cooling, especially when installed on ground floors [6, 7], Birchfield and co-workers [6], using computer simulation of heat transfer in resi dential and light commercial structures, estimated the energy and cost savings resulting from the installation of various carpet assemblies. Hager [10] contends, however, that the energy-saving potential offloor cov erings is less significant because the percentage heat loss through ground floors is minimal, and only a small fraction ofthe heat loss would be saved by add ing floor coverings. laynSst^thebuildirigimliistry statistics estimate tiagwaUs aremajdaddiitributdrf-to heat Ids. A report from the California Energy Commission [11] states that the major source of heat loss in homes is through walls. Dow Chemical Company estimates that a typ ical house with moderate amounts of insulation loses up to 17% of its heat through the walls [9]. Many of the homes in California, as in other states, are energy inefficient and poorly insulated because they were built during a time when energy was cheap and plen tiful. Thus, wall insulation in these homes is often inadequate. Because-of the larger .percentage of wall areaT there is a greater opportunity to save energy with wall coverings, compared to floor coverings. Studies by Haynes [11], Ball [5], and the Carpet and Rug Institute [6, 7] showed that the thermal con ductivity of a floor covering material is inversely pro portional to thickness. Other researchers also showed a linear relationship between thermal resistance and the thickness of a textile product [I4|. Since the ther mal insulative value ofair is significantly greater than that of fibers, the insulative properties of a textile 'S 19S2 Textile Research Institute 0040-31 75/82/0110-0703501.00/0 BFG08379 704 Textile Research Journal material are largely dependent on the amount of air trapped within its structure (8,. 14]. Both density and thickness determine the thermal insulation potential of a textile. Napped and pile fabrics, for example, usually have a greater thermal insulating value than do fabrics with smooth surfaces. Polyurethane and polyester foams with fine pore structures trap air more effectively than do fabric structures and, hence, have good insulating efficiency [14], Thus..wall coedDgftwiihjnatast&lhicknSs^andibUityto may"significahtly='fe3uce' energy- cdnsumpnotr-'fbr heaun^Jtudicoohnfc-'mfrTCsidcntial.;and- commercial ?HiiiiUTes.^neasuch-fnaterial-tV-a-nonwovea_polx-. pBopylenejtwalPcbvering-material that- waj-designed ,10^340videtboth^theimaf-and-'acoustical-insulation. According to Protospataro and Oliviera [IS. 16], the product's thermal insulation depends on both the characteristics of the component fibers and the struc ture of the fabric itself. The construction characteristics of wall coverings are an important criterion for selection, both from the aesthetic and functional standpoint. Leuman [131 states that surface quality or texture, because of its insulating ability, is often chosen over color and other desirable characteristics. The nonwovens, for exam ple, have disadvantages such as instability, suscepti bility to indentation, and problems in application. Consequently, nonwoven fabrics have not achieved the status of more traditional wall covering materials. Few studies have evaluated the thermal character istics of textile products suitable for wall coverings. Our study evaluates the thermal insulative properties of selected wall covering fabrics differing in fiber and fabric construction characteristics and type of pri mary backing. The wall covering fabrics evaluated included natural and man-made fibers, nonwoven and woven fabrics, and cork fabrics. Additional fac tors considered when selecting the test fabrics were availability in continuous form, compressibility, di mensional stability, popularity, and functionality such as acoustical and potential insulative propenies. The study was limited, however, to evaluating the thermal insulative propenies. thickness, weight, bulk density, fiber content, and construction characteris tics of the wall covering fabrics. Experimental Procedure Materials Fifteen wall coverings were tested: they were se lected as representing a variety of both natural and man-made fibers and materials, and woven and non woven fabric constructions. The fiber content, con struction characteristics, weight, thickness, and den sity of the wall covering materials are presented in Table 1. Photographs and illustrations depict surface and construction characteristics (Figures 1 and 2). Three specimens measuring 32 X 52 cm were ran domly cut from a 2 m length of each wall covering material. All test specimens were placed under stan dard conditions (65 2% RH and 21 l*C) for 24 hours prior to testing for thickness, weight, and ther mal properties. Fabric A B C 0 E F C H 1 J K L M N o Weight . g/m; 637.43 36S.60 464.17 718.81 727.62 435.01 335.33 328.35 36I.7S 567.23 451.63 3X7 60 1.9X3.20 2,306.96 2.X7K.96 Tam.1 I. Construction characteristics of wail coveting fabrics. Thickness mm Bulk density Fact Backing 0.914 1.422 2.23 J 1.219 1.293 1.600 1.016 0.864 1.1 IV 1.194 1.854 2.438 5.6*1 6.071 7 0X7 697.41 399.86 207.68 389.67 561.87 271.88 330.05 380.27 323.60 473.08 243.60 241.02 jaa.&d 380.00 406.23 natural cork, seam sliced veneer natural cork, random sliced veneer natural cork. 6 mm granules expanded vtnyi expanded and embossed tmyi acrylic and modacryiic novelty yarns jute warn, polyester (tiling 10O* flax. 22 x Z\ plain weave, pigment prim 100% flax. 10 x 10 plain weave cotton warp, flax filling 100* wool. 16 x 12 plain weave cution Ailing, paper warp 1 (Xn sisal, vertical curds IOC* sisal, vertical braids Mend of wool. mohair, rax on. nylon, modacryiic: unitary' fusion bonded concentric rib 1009 cotton. 51 X 45 piain weave 1009 cotton. 51 _x.46 plain weave 1009 cotton. 74 x 40. 2/1 twill 1009 cotton. 64 X 41 plain 't 100% cotton. 64 * 41 plain weave paper paper none paper paper paper paper laic* 1009. jute KMI% juli* 095G003 BFG08380 Novumbur 1982 705 Figure I. Cress sectional diatnms of wall covering fabrics (W warp and F lining). The construction characteristics and liber contents of the face and backing materials in the wall coverings were evaluated according to the procedures in the following standard test methods: ANSI/ASTM D 418. Woven and Tufted Pile Floor Coverings: ANSI/ aSTM D 1910. Construction Characteristics of Woven Fabrics: ANSI/ASTM D 2646. Testing Back ing Fabrics: and AATCC Test Method 20. Fibers in Textiles: Identification [1. 2]. A fiberglass insulating board with a known thermal conductivity value was obtained from the National Bureau ofStandards and used to calibrate the guarded hot/cold plate. T HICKNESS The procedures in ANSI/ASTM D 1777, Measur ing Thickness of Textile Materials (2) were used to measure the thickness of the wall covering materials. Thickness measurements were taken with a Frazier Compressometer under 0.07 k N/m; load, using a presser foot with a 7.6 cm diameter. An average of five readings was recorded for the thickness of each specimen. Fabric Weight and Bulk Density Fabric weight in g/mJ for each wall covering was based on the average weight of three 25.4 x 25.4 cm specimens [2]. Bulk density was calculated as follows [2]: B - Wit . where 3 m buik density, kg/m3: W/ " mass/unit area of fabric. g/m~. and t m thickness of fabric, mm. Thermal Transmission The procedure in ANSI/ASTM D 1518 [1] was used to measure the thermal transmission character istics of the wall covering fabrics. The testing instru ment was a guarded hot/cold plate, constructed at Kansas State University for the Department of Cloth ing, Textiles and Interior Design, and housed in the Institute for Environmental Research. The guarded hot/cold plate is composed of a test plate and a guard ring, which can be maintained at a constant temper ature during testing. Thermal transmittance was mea sured by the rate of heat loss through the fabric into BFG08381 20956604 706 Textile Research Journal i)03SG0Z ..as Ficuiu 2. Phoiotraphi of wall covcrini fabrics. the air by recording the amount of energy required to maintain the test plate at a constant temperature. To determine the amount of power loss, we first calibrated the instrument by using a material with a known thermal conductivity coefficient: a fiberglass insulation board from the National Bureau of Stan* dards. The guarded hot/cold plate was operated in a Sherer environmentally controlled test chamber which measured 2.44 x 3.05 m. The test conditions in the chamber were 20.25 0.5*C, 50% RH. and air ve locity of approximately 10 cm/sccond. The temper ature of the test plate and guard ring was maintained at 34.0 0.4*C. After the specimens had reached BFG08382 November 1982 707 equilibrium with the conditions in the test chamber, readings from the specimens were taken every 3 min utes over a 30 minute period, resulting in 10 readings per test. The intrinsic thermal transmission coefficient of the test fabric alone. CA, was calculated using Equa tion I, based on values derived from the combined heat or thermal transmittance coefficient of the spec* imen plus air. U,. and the bare plate thermal trans mittance coefficient. (J^ Equation 2 was used to cal culate Ui. and Uwas similarly calculated using the bare plate thermal transmittance coefficients. Ut, /*, and were expressed in Btu/h fri *F.` L'i - (*x Ut) (1) U, - (P/{A x (- T.)) . (2) Thermal Coni5uctivitv Mean thermal transmittance coefficients (/-) and specific thermal conductivity coefficients (k) for the wall coverings as measured by the guarded hot/cold plate are reported in Table 11. The analysis of variance statistical test showed that differences among the 15 wall coverings were significant at the 1 % level for both the thermal transmittance (/:) and thermal conduc tivity coefficients (k). Table It. Thermit conductivity of w|I covering fabrics. Fabric Thermal transmittance coefficient ( Btu/h fr-'F1 Specific thermal conductivity coefficient (A) Btu-in/h-ft:-*F" where P power loss from test plate, Btu/h: A * area of test plate, ft*; T, test plate temperature, *F; and T. - air temperature. *F. After the thermal transmittance coefficient had been calculated. Uz, the specific thermal conductivity coefficient for a unit thickness of test specimen, k, also was calculated using Equation 3 k * Uz X thickness, in. . (3) Results A s c Da F G H l J K L M N O 4.444 4.206 3.4S9 6.129 6.S02 4.354 6.703 5.144 5.630 5.160 3.724 3.377 UU 2-260 1.654 0.160 0.236 0.307 0.291 0.332 0-275 0.268 0.175 0-24* 0-2*3 0.272 0.324 0.602 0.504 0.462 Construction Characteristics Tho^wllj<overingsrevaluated7in this'study were representativeofthe" t^jes currently available-Pres- idenrial^and-'ctunjaisaa^OteriQlaspRbnc'weights ranged from 328.55 g/m1 2.878.96 g/m: (tM^^^JpShSimilarfy, fabric thickness ranged from 0.864 mm (0.034 in.) to 7.087 mm (0.279 in.) Fabric construction types included three cork mate rials laminated to cotton backings (fabrics A, B. and C): tvtfexpanged vinyls laminated to cotton backings (fabricsDand E)?six medium-weight fabrics in which yams or woven fabrics were bonded to paper backings (fabrics F. G. I. J, K- and L): one unbonded, pigment- printed linen (fabric H): two heavy-weight, 10096 sisal fabrics with a latex backing or bonded to jute (fabrics M and N): and a unitary, fusion-bonded, concentric rib fabric (fabric O). Fabrics M. N. and O were similar in weight and thickness to textiles used for floor cov erings. Photographs of the fabric surfaces and schematic drawings oftheir cross sections illustrate the construc tion details (Figures 1 and 2). 1 To convert 10 W/(m; K). multiply by 5.67. To convert to W/(m: KL multiply by 3.67. to W/(m K). multiply by 0.144. * To convert (fAkweie-iaverselv proportional to the thickness of .yu^waUpcaverinssT The TJuncarfs-Multiple Range Test (Table III) was performed on mean thermal transmittance coefficients to identify significant dif ferences in the thermal properties among the wall coverings. TJie'-thinhespaiffiS (i.e.. fabrics G, E, D, I, J, H. and A) exhibjted.thejughea thermal.uaiuumtanae coefficients or were the poorest insulators. Fabric G. which was constructed from heavy jute yams inter laced with a fine polyester ftlling.-exhibited the highest thermal transmittance coefficient </.e., was the poor est insulator), even though it was slightly thicker than fabrics H (100% flax) and A (natural cork, seam sliced veneer). This may be attributed to the paper backing, the lower insulative properties of the jute fibers, and the spaces between the warp yams. The expanded vinyls (fabrics D and E) also exhib ited significantly higher thermal transmittance coef ficients than fabrics I, 3, H, and A, which had con siderably lower thickness values. The latter wall eov- BFG08383 f 5 i i ii ii A I 70S Textile Research Journal Table III. Duncan's multiple range test for the thermal transmittance coefficients of wall covennf fabrics. Fabric C E D 1 i H A Thermal transmitLance coefficient ( Blu/h-ft^-'F'* 6.703 6.502 6.129 * 5.630 5.160 5.144 4.444 Groupings" ' F 4.354 a 4.206 K 3.724 C 3.489 a l 3.377 M 1688 N 12SO O 1.654 * To convert to W/(m- K). multiply by 5.67. ` Means con nected by asterisks are not significantly diffcrenL alpha level - 0.05. erings were either woven fabrics or seam sliced veneer cork. The thickness and thermal transmittance coeffi cients for the thicker wall coverings were inversely correlated (i.e.. thickness: fabrics K < C < L < M < N < O; thermal transmittance [L'r]: O > N > M > L > C > K). The fusion bonded concentric rib fabric (fabric O) had a Uj of 1.654 which was signif icantly lower than all other fabrics tested. It thus pro vided the greatest amount of insulation against heat loss. Thermal conductivity coefficients (k) were calcu lated to ascertain the effects of fiber type and yam and fabric construction characteristics on thermal conductivity per unit thickness (Btu in/h ft: *F).: The.rank .order-,oC. the-thermah conductivity coeffi cients (k) differed from the thermal transmittance coefficients indicating that fiber and fabric con struction characteristics significantly affected the ther mal insulative properties of the wall coverings. The Duncan's Multiple Range Test (Table IV) showed that the 100** sisal wall coverings (fabrics M *' To cimven ui W/(m K). multiply by U. 144. and N) provided the least amount of insulation per unit thickness. This may be attributed to fabric con struction characteristics (i.e., lengthwise braids) or the inherent characteristics of the sisal fibers, such as lack of fiber crimp and length of the staple. The spaces between the vertical ribs in fabric M may have con tributed to its high thermal conductivity coefficient, which was significantly greater than that of fabric N. Table IV. Duncan'i multiple range test Tor thermal conductivity coefficients of wall covering fabrics. Fabric M N O E Specific thermal conductivity coefficient (A) Btu in/h "F* *0.602 0.540 0.462 0.332 Groupings* *- L 0.324 C 0.307 D 0-291 F 0.275 K 0272 G 0268 I 0248 J 0243 B 0.236 H 0.175 A 0.160 * To convert to W/(m K). multiply by 0.144. * Means con nected by asterisks are not significantly difTerenL alpha level >0.05. The unitary fusion bonded, concentric rib (fabric O), which was a blend of wool, mohair, rayon, nylon, and modacrylic fibers, exhibited a significantly lower thermal conductivity coefficient than did the 100% sisal fabrics (fabrics M and N), but the value was significantly higher than values obtained for the other wall coverings. -The spaces.,between, the vertical ribsmay have'contributed to the increased heat loss. We observed no significant differences in thermal conductivity among fabrics E (expanded and em bossed vinyl with vertical ribs). L (cotton filling and paper warp), and C (natural cork with 6 mm gran ules). These wall coverings ranked below fabrics M. N. and O. as described above, and thus exhibited greater thermal insulation. The other cork wall cov- *1X495602 BFG08384 November 1982 709 enngs showed significantly lower thermal conductiv ity values than did the wall covering constructed from cork granules. Once again, the loss of insulation in the granulated cork fabric may be attributed to the appreciable spaces between the 6 mm granules that adhered to the primary backing. The expanded vinyl with vertical ribs (fabric E) had poorer insuiative properties than did the expanded vinyl without vertical ribs (fabric D). We observed no significant differences in thermal conductivity for fabrics F (acrylic and modacrylic novelty yams laminated to paper), K (100% wool laminated to paper), G (jute warp and polyester fill ing laminated to paper, 1 (100% flax plain weave lam inated to paper), and J (cotton warp and flax filling laminated to paper). It appeared to us that the paper backing negated differences in thermal conductivity among these various fiber and fabric types: however, the complex interaction between backing, fiber type, and yam and fabric construction characteristics must not be oversimplified. Further research is needed to evaluate the effects of various backing materials on the thermal conductivity of wall coverings. Fabrics B (natural cork, random sliced veneer), H (100% flax), and A (natural cork, seam sliced veneer) exhibited the lowest thermal conductivity coefficients or provided the greatest amount of insulation. Even though the fiber microstructure, long staple length, and low crimp in flax fibers usually provides less in sulation than highly crimped, shon staple length fi bers such as wool or texturized synthetic fibers, the balanced weave and absence of paper backing in Fab ric H may have contributed to its lower thermal con ductivity values. Conclusions Fifteen wall covering fabrics, that may have poten tial for reducing heat loss through interior walls in residential and commercial buildings were evaluated for thermal characteristics using a guarded hot/cold plate. The fabrics differed in weight, thickness, fiber content, type of backing, and construction charac teristics. Thermal characteristics evaluated included ther mal transmittance (C/j) and specific thermal conduc tivity coefficient (Ac), which is based on heat loss or conductivity per unit thickness. Results showed that vertical cords, braids, and ribs increased heat loss in the wall covering fabrics. Sim ilarly, granulated cork wall coverings with appreciable spaces between the granules exhibited higher con ductivity than did veneer-type cork fabrics. Addi tional research is needed to assess the effects of the backing material on the thermal characteristics of wall coverings. Literature Cited 1. Am. Assoc. Textile Chemists and Colorists. "AATCC Technical Manual." 1980. 2. Am. Soc. Test. Mat.. "Annual Book of ASTM Stan dards." Part 32. 1980. 3. Anon.. Fiber and Textile Wall Coverings. Textiles. 4(2). 31-56 (1975). 4. Anon., Tufted Pile Wall Coverings Lowers Sound Level. Am. Textile Rep. 84. 16 (1970). 5. Bail. H. D.. and Nevins. R. G.. "Carpets and Environmenu Phase I-Thermal Properties of Carpets. Phase 11-Physical Environment and Operating Costs." Insti tute for Environmental Research. Kansas State Uni versity. Manhattan. Kansas. 1967. pp. 1-23. 6. Birchfield. J., Combes. R. S.. and Olson. L. H.. "Ad vantages ofCarpet and Rugs in Energy Conservation." Carpet and Rug Institute, 'Dalton. Georgia, 1976. 7. Carpet and Rug Institute. "Advantages of Carpet and Rugs in Energy Conservation." Dalton, Georgia. 1977. 8. Crow, R. M-. "Heat and Moisture Transfer in Clothing Systems. Part 1: Transfer through Materials, A Liter ature Review," Defense Research Establishment. Ot tawa. Technical Note No. 74-27. Department of Na tional Defense. Canada, pp. 4-ig. 9. Dow Chemical Company, Buying a Well Insulated House. Hudson Home Magazine, 1979. 10. Hager, N. E- Energy Conservation and Floor Covering Materials. ASHRAE J. 19. 34-39 (1977). 11. Haynes, B. C.. Simons. J. W,, McDougaL K. F,, and Mize, J. J, Thermal Properties of Carpets and Drap eries, University of Georgia. College of Agriculture. Experiment Stations and USDA Agricultural Research Service, Research Bulletin 68, 1969, pp. 1-34. 12. Legislative Issue Memorandum. Achieving Energy Ef ficiency in Existing Buildings. California Energy Com mission Staff. 1980. pp. 1-31. 13. Leumann. G_ Use of Nonwovens for Wallpaper Lin ings and Other Insulating Products in Housing. Index 78 Conge Rap. Build. Instil. 2. 2.14.1-2.14.2 (1978). 14. Monego. C. 3.. Golub. S.. Baker. C. A.. Gesmer. B. S.. Kaswell. E. R.. Kobayashi. F. F.. Monroe. E. F.. and Panto. J. S.. Insulating Values of Fabrics. Foams and Laminates. Am. Dyes Rep. 52, 6--17 (1963). 15. Protospataro. F.. and Oliviera. P.. Veehnical Progress in Polypropylene Wall Coverings, Carpet Rug Ind. 4, 12-16 (1976). 16. Protospataro. F.. and Oliviera. P.. "Polypropylene Wall Coverings. International Conference: Polypropylene Fibers in Textiles," University of York, September 30October I, 1975. pp. C4.I-C5.5. 17. Whiton. S.. "Interior Design and Decoration." J. B. Lippincott Company. New York. 1976. p. 506. W#9Mjrfffir wmW iViwAfp V. /W/ BFG08385