Document Gmzz7ZOb15KZ1mQRE17e9mz6v

>190 >. CHAPTER 9 1958 Guided Table 8. Coefficients of Transmission (U) of Masonry Cavity Walls* T Coefficient* are expressed in Btu per (hour) (square foot) (Fahrenheit degree difference in temperature between__ the air:on the two sides), and are based on an outside wind velocity of 15 mpk. Example Example of Substitution Resistances used are given below in this Resistances used are given below in table or <tn* 7TaMbJle. 5o__r/4 ath.i-s. jta-Lblle___o_rmin_tiT_abl_e 5 or 4. Construction Resistance (R) .1. Outside surface (15 mph wind) 0.17 2. Common brick (4 in.) (av. R.) 0.76 3. Air space**...................................... 0.97 4. Concrete block (gravel agg.) (4 in.)........................................0.71 5. Airspace........................................ 0.97 6. Gypsum lath (% in.).................. 0.88 7. PLaa. (It. wt. agg.) Vi in............O.St 8. Inside surface (still air).......... 0.68 Total resistance......................... 4-90 U = l/R = 1/4.90 =...............0.20 See value 0.20 in bold face type in table below. To Adjust U Values for Construction with Added Insulation6 between Inner and Outer Tiers or between Furring Strips, See Table 16. Replace item 4 with 8 in. concrete block and items 6 and 7 with % in. plas. (sand agg.) applied directly to concrete block. Total resistance............................4.90 Deduct 4. Concrete block (gravel agg.) 4 in........................................... 0.71 5. Air space....................................0.97 6. Gypsum lath (H in.)........... 0.31 7. Plas. (It. wt. agg.) yi in....... 0.88 Resistance deducted........8.88 Difference............................8.(8 . Add 4. Concrete block (gravel agg.) 8 in........................................... 1.11 7. Plas. (sand agg.) % in..........0.11 Resistance added.............. 1.88 .- Total resistance =............. 3.30-' V - \/R - 1/3.80 =........O.M Inter ior Finish 1 d I_L an s. id E 'g S 3 g o h a t l aP . Exterior Construction Inner Section Metal Gypsum Lath HPlas AND $4 IN. ON IN. Lath (% in.) AND Wall Plas. in. Plas. a fc on Fur on Furring ring o idn oo >4 W 1 1 Resistance r [S th si aS5< CD . 3-* d<3 00 553 . M oPt. 2 T3 a . 03<? D e* 1 o T3 W a a ' a 0<3 < JH*7 DO 0.11 0.89 0.18 0.47 0.88 Mi 0.64 1-48 1.58 Material Av. R. Material R u u U U U U u U V U u y-;.. Face brick (4 in.) Ufa. Concrete block (4 in.) (Gravel agg.)................ 0.71 0.34 0.32 0.30 0.25 0.23 0.23 0.23 0.22 0.19 0.18 0.23 V5 0.44 (Cinder agg.)................. (Lt. wt. agg.)................. 1.11 0.30 1.60 0.27 0.29 0.26 0.27 0.24 0.22 0.21 0.21 0.19 0.21 0.20 0.21 0.19 0t20 0.19 0.17 0.16 0.17 0.16 0.21 o.w.r Common brick (4 in.)... 0.80 0.33 0.32 0.29 0.24 0.22 0.23 0.23 0.21 0.18 0.18 Clay tile (4 in.)................ 1.11 0.30 0.29 0.27 0.22 0.21 0.21 0.21 0.20 0.17 0.17 0.21 Concrete block Concrete block (4 in.) . (Gravel agg.)..... ........... (Cinder agg.)................. 0.71 0.30 0,29 0.27 0.23 0.21 0.22 6.21 0.20 0.18 0.17 1.11 0.27 0.26 0.25 0.21 0.19 0.20 0.20 0.19 0.16 0.16 .; ,, 0.76 (Lt. wt. agg.)................. 1.60 0.25 0.24 0.22 0.19 0.18 0.19 0.18 0.18 0.15 0.15 (gravel agg.) (4 in.) 0.7f Common brick (4 in.)... 0.80 0.30 0.29 0.27 0.22 0.21 0.21 0.21 0.20 0.17 0.17 ?!:m Clay tile (4 in.)................ 1.11 0.27 0.26 0.25 0.21 0.19 0.20 0.20 0.19 0.16 0.16 0.20:-? r- (cinder agg.) (4 in.) i.n Concrete block (4 in.) . ^ h- (Gravel &rz.)................. 0.71 0.27 0.27 0.25 0.21 0.20 0.20 0.20 0.19 0.17 9.16 0"r . (Cinder agg.)................. 1.11 0.25 0.24 0.23 0.19 0.18 0.19 0.18 0.18 0.16 9.15 O.lS^r* (Lt. wt. agg.)................ 1.60 0.23 0.22 0.21 0.18 0.17 0.17 0.17 0.17 0.15 0.14 Common brick (4 in.)... 0.80 0.27 0.26 0.24 0.21 0.19 0.20 0.20 0.19 0.16 0.16 Clay tile (4 in.)................ 1.11 0.25 0.24 0.23 0.19 0.18 0.19 0.18 0.18 0.16 0.15 0.l8;V-> * See text section Calculating Overall Coefficients for basis of calculations. b To adjust U values see note just above this table. c If insulation is to be used in the cavity it should be a water resistant type. . - l Heat Transmission Coefficients of Building-Materials 191 Table 9. Coefficients of Transmission' (U) of Frame Partitions or Interior Walls" Coefficients are expressed tn Btu per (hour) (square foot) (Fahrenheit degree difference in temperature between the air on the two sides), and are based on still air (no wind) conditions on both sides.. Example Resistances used are given below in this table or in Table S or 4, Construction Re' "" . 0.85 . 0.88 . 0.97 . 0.88 5. Surface (still air). . 0.68 U = l/R = 1/8.97 . . 8.97 . 0.34 i table Example of Substitution Resistances used are given below in this table or in Table S or 4. board (H in). Total resistance.............................. . 8.97 - Deduct 2. Gypsum wall board (H in.).. . 0.88 Difference................................ . 8.65 Add 2. Hardboard (H in.).................. . 0.18 Total resistance.................... . 8.88 (/!/ = 1/8.88 -.......... . 0.35 To Adjust U Values for Construction with Added Insulation between Mem bers, See Table 16. Type of Interior Finish Single Partition (Finish on Only One Side op Studs) Double Partition (Finish on Both Sides of Studs) Material R Gypsum bd. (% in.)........................................................................................ Gypsum lath (H in.) and W in. plas. (It. wt. am.)........................... Gypsum lath (% in.) and in. plas. (sand agg.).............................. Metal lath and M in. plas. (It. wt. a*cg.).................................................. Metal lath and 44 in. nlns imnd nvtr ) Insul. bd. (V4 in.) insul. bd. lath (J4 in.) and Yi plas. (sand agg.) ............................ Plywood: (H in.)................. (H in.)................................................. . .............. (H in.).............................................................................................. Wood panels (44 in.) Wood-lath and Vt in. Dias, (sand ) Sheet metal panels Glass and (class blocks 0.88 0.64 0.41 0.47 0.18 1.4S 1.68 0.81 0.47 0.68 0.94 0.40 0 UU 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 0.34 0.28 0.32 0.31 0.39 0.19 0.19 0.34 0.31 0.28 0.24 0.32 0.43 See Table 20 To adjust V values see note just above this table. tion of heat flow. Each part is based on temperature conditions considered generally appropriate for the case. Any and all U values are based on a series of assumptions as to nominal characteristics. Common variations in conditions, materials, workman- ?. P> e^c- can introduce much greater variations in U values than the varia- 10ns resulting from the assumed mean temperatures and temperature dif- sie6"fieS ^ecribed. From this it is also clear that the use of more than two no 1u?an*' in stating a U value is assuming more precision than can pssibly exist. Three significant figures are used in Table 16 merely as a to nht re . cing cumulative errors when the table is used several times accurnfln a s*n*e result- It should not be assumed that the figures are Table ir' ?ver'a^> to three significant figures. Also, a result taken from t) should always be rounded off to two significant figures. (Tort continued on page 202)