Document Oz77bdQ247m8wYzk1KBEbv0vM

118 CHAPTER 9 1960 Guide Table 9 ..., Coefficients of Transmission {U\ of Frame Partitions or Interior Walls* Coefficient* are expressed in Btu per (hoar) (apror* feof) (Fahrenheit degree difference in teaperefwe behwen the air oa 6m two tided, and are boted on *tiS air (no wind) condition* eo both ride* Example--Wcti S I Example of Sebtlilvtio* Resistances used are given below in this table or in Table S or 4 Construction Resistance (R) 1. Surface (still air)................................................ 0.68 2. Gypsum bd. 04 in.).............................................0.3* 3. Air space*................................................................0.97 4. Gypsum wall board 04 in.)................ 0.38 5. Surface (still air)................................................ 0.68 Resistances used are given below in this table or in Table S or 4 Replace item 2 with wood fiber hardboard ($ in.). Total resistance....................................................... 8.97 Deduct 2. Gypsum wall board 04 in.).............. 0.3* Difference................................................................. 8.66 Add 2. Hardboard04 in.)..................................... 0.13 Total resistance.................................................. 8.97 Total resistance...................................................... 8.83 V - i/s - 1/2.07............................................... 0.34 U 1/R - 1/0.85 -..................... 0.35 See value 0.34 io boldface type in table below. To Adjust U Vakms far Cenfmdioa with Added Awtrino between Mtobtn, See Tati* 16 Type of Interior Finish Stag!* Partition (Rn2d> oa Only On* Sid* of Studs) Double Partition (Raid) on Both Sides of Sfed*) Moferial Gypsum bd. 04 in.)............................................................................................................ Gypsum lath (H in.) and \4 in. Dias. fit. wt, age.)...................................... .... Gypsum lath 04 in.) and 14 in. plas. (sand agg.)................................................... Metal lath and in. plas. (It. wt. agg.).................................................................... Metal lath and in. plas. (sand agg.)........................................................................ Insul. bd. 04 in.)................................................................................................................. Insill. bd. lath 04 in.) and )4 plas. (sand agg.)....................................................... Plywood: 04 in.).................................................................................................................. ($4 in.)................................................................................................................ 04 n.).................................................................................................................. Wood panels 04 in.)........................................................................................................... Wood-lath and \4 in. plas. (sand agg.)........................................................................ Sheet-metal panels........................................................................................................... Glass and glass blocks........................................................................................................ * See text acettoo Oelrafetitig Overall Coefficacata for bem of cefeufeiios*. * To adjust 0 value* lor the eSeet of added iosulatioo between framine member*. aae Table 10. 0.38 0.64 0.41 0.47 0.13 1-43 1.68 0.31 0.47 0.63 0.94 0.40 0 U A 0.60 0.50 0.56 0.55 0.67 0.36 0.35 0.60 0.55 0.50 0.43 0.57 0.74 See Table 21 U t 0.34 0.2S 0.32 0.31 0.39 0.19 0.19 0.34 0.31 0.28 0.24 0.32 0.43 1 1 a 3 4 6 6 7 8 9 10 11 12 13 flow through 2 x 4 in. (nominal) studs, 16 in. oo centers, the framing covering 15 percent of wail area, as shown in Fig. 7. Thermal resistance for gypsum board and insulating board apply equally to plain material and to those which may be decorated at the factory or on the job. In order to condense the tables an average resistance value (Av.R) has been used in some tables for types of materials hav ing approximately the same thermal resistance values. The dif ference between the average value and the exact value for any given material usually causes no significant change in the re sulting U value. ' Actual thicknesses of lumber assumed to be as follows: Nominal Actual Nominal Actual 1 in. (S-2-S)......... in. 3 in. (S-2-S).................2H in. \H in. (S-2-S)......... iKe in- 4 in. (S-2-S)....................3*$ in. 2 in. (S-2-S).......... 1% in. Finish flooring, 2M in. (S-2-S)......... 2%in. (maple or oak)............... > in. It should be noted that the effects of poor workmanship in construction and installation have an increasingly greater percentage effect on heat transmission as the coefficient be comes numerically smaller. Failure to meet design estimates may be caused by lack of proper attention to exact compliance with specifications. A factor of safety may be employed as a precaution when it is judged desirable. Insulating Materials In order to determine the benefit derived ham the addition of insulating materials to a given construction, the overall coefficient of heat transmission Ut of the inMilatArl construc tion may be compared with (he corresponding coefficient U without insulation. Table 16 (Part A to Part E) and Fig. 7 may be used for determining the coefficients of transmission of constructions with any combination of fibrous, bulk, or mass insulation and air spaces of various effective emiasivities. Example 8: Find the coefficient of transmission of a frame wall consisting of i4 x 8-in. bevel lap wood siding, building pa- (CeMieutd * f. Itl) Heat Transmission Coefficients of Building Materials 119 Table 10 .... Coefficients of Transmission ((/) of Masonry Partitions* Coefficient* or* expressed m Btu par (bow) faoor* feet) (Fahrenheit d*gr* difference t temperature between the air oa the too d*r), and are bared on stUt air (no wind) coodilions oo botil tides Exempt*--WaB C 2 Exempt* of SvbsfiMioa Resistances used are given below in this table or in Table 3 or 4 Construction Resistance (R) 1. Inside surface (still air).................................... 0.63 2. Pias. (It. wt. agg.) % in...................................... 0.69 3. Cement block (cinder agg.) (4 in.)................. 1.11 4. Plas. (It. wt. agg.) $$ in.................................... 0.39 5. Inside surface (still air).................................... 0.68 Resistances used are given below in this table or in Table 3 or 4 Replace item 3 with gypsum tile (4 in.) Total resistance....................................................... 3.86 Deduct 3. Cement block (cinder agg.) (4 in.).. 1.11 Difference................................................................. 8.14 Add 3. Gypsum tile(4 in.).................. 1.67 Total resistance.................................................. 8.86 Total resistance..................... 3.81 U = 1/R -- 1/3.35 -....................................... 0.31 G - 1/R - 1/3.81 -.............................................0.26 See value 0.31 in boldface type in table below. Type of Portitioo Material Hollow concrete block (Cinder agg.) (Lt. wt. agg.) Surface Finish KesUtaoce ^---------- Non* U A Pico. (ft. wt. ub4 $ to. Ptov (sand *BflJ H to. Ooe tide Two tide* On* side Two tides 0.3? 0.78 on 0.22 UU uU c 0 E Number 0-40 0.32 0.38 0.38 0.35 0.29 0.27 0.33 0.27 0.31 0.34 (Gravel agg.) Hollow clay tile (6 in.)........................................................................ (8 in.)........................................................................ Hollow gypsum tile (4 in.)........................................................................ Solid plaster walls Gypsum lath 04 in.) and plas. yi in. each side 1.88 1.86 1.67 1 in. each side Metal lath and plas.b 2 in. total thickness 2)4 in. total thickness 0.46 0.38 0.35 0.31 0.33 0.33 0-28 0.29 0.29 0.25 0.26 0.36 0.30 0.32 0.37 0.35 0.37 0.29 0.31 _ _ _ _0.36 0.48 _0.32 __ _ _ _ _ _ _0.38 0.58 _0.55 _ _ _ 10 14 16 32 24 Bee text aectioo CUcoUtint Overall Coefficient* tor bad* at ' Metal core and rapport* disregarded- Plaster troweled smooth both aide*.