Heating and ventilating buildings : a manual for heating engineers and architects . be shownthat the heat transmitted by multiple glass will bear the following pro-portion to that transmitted by a single thickness: Number of glass 1 2 3 4 « 212 2Proportion of heat transmitted 1 — — — v 3 2 5 1 + « The following tables of the coefficients for the thermal conductivity ofpoor conductors are taken from Peclets work and are included herefor reference. The results will be found essentially the same as given byvarious authorities in the table in the appendix. CONDUCTION OF HEAT FOR ONE DEGREE DIFFERE
Heating and ventilating buildings : a manual for heating engineers and architects . be shownthat the heat transmitted by multiple glass will bear the following pro-portion to that transmitted by a single thickness: Number of glass 1 2 3 4 « 212 2Proportion of heat transmitted 1 — — — v 3 2 5 1 + « The following tables of the coefficients for the thermal conductivity ofpoor conductors are taken from Peclets work and are included herefor reference. The results will be found essentially the same as given byvarious authorities in the table in the appendix. CONDUCTION OF HEAT FOR ONE DEGREE DIFFERENCE OFTEMPERATURE PER HOUR. Per DegreeFahr. Material. Gray marble, fine-grained White marble, coarse-grained Limestone, fine-grained (mean of three samples).Limestone, coarse-grained (mean of two samples) Plaster of Paris Brick Powdered brick, coarse-grained , Fir at right angles to the fibres Eir parallel with fibres Walnut at right angles to the Walnut parallel with fibres Cork Glass Sand Wood ashes Powdered charcoal Powdered coke Cotton, raw or woven Paper. AMOUNT OF HEAT REQUIRED FOR [VARMING. 79 The following table for coefficient of convection K, as calculatedfrom the last formula, Article 45, is taken from Peeiets work : TABLE GIVING VALUES OF A FOR VARIOUS HEIGHTS INMETERS FOR A PLANE VERTICAL SURFACE. Heights,Meters. A. Heights,Meters. A. 2 3 4 2. 08 5 10 15 20 The table shows a decrease in the coefficient of convection with in-crease in height in a vertical wall as explained in Article 45. This de-crease is calculated from the hypothesis that the air which is heated riseswhile remaining in contact with the body, and for this reason has itscapacity diminished for absorbing heat. This hypothesis is doubtlesstrue in the case of absorption of heat by air-currents from radiatorsor heated bodies, but is probably considerably in error for walls of buil
Size: 913px × 2738px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyo, bookyear1910
