. Ventilation for dwellings, rural schools and stables. ground. The fact of wind velocity increasing with Defective Outtake Shelter. 51 hight above the ground is expressed in Fig. 22 by thelength of the arrows, these being aprpoximately propor-tional to the wind velocities at such levels. It will be clear from what has been said that the top of achimney or a ventilating flue should rise well above theridge of the roof, where the wind has a clear sweep, and notend just above the eaves as is the case illustrated in Fig. 23. So, too, it must be clear that anything which checks thevelocity of the
. Ventilation for dwellings, rural schools and stables. ground. The fact of wind velocity increasing with Defective Outtake Shelter. 51 hight above the ground is expressed in Fig. 22 by thelength of the arrows, these being aprpoximately propor-tional to the wind velocities at such levels. It will be clear from what has been said that the top of achimney or a ventilating flue should rise well above theridge of the roof, where the wind has a clear sweep, and notend just above the eaves as is the case illustrated in Fig. 23. So, too, it must be clear that anything which checks thevelocity of the wind across the top of a chimney or ventilat-ing flue, or which resists the escape of air from them, mustreduce the power of the wind to produce draft. Such caps,therefore, as are seen in Fig. 23 and as is represented on alarger scale in Fig. 24, designed to kec]) out the storm, mustnecessarily materially reduce the draft and should beavoided wherever possible unless forced ventilation has beenadopted and the current is maintained by FIf?. 2J. SluIfcr for \mtilafin>? i! --iicfl for hiph efflcioncj- in kooiv ing out rain but wiiirli ma: nducos the drnft In nntural ventilation. ]\rany forms of cowls have bceji d<vised to prevent down-draft in chimneys and ventilating flues, and with a vi«W toutilizing the wind to better advantage in producing will seldom happen, however, that these nerd be resortedto in the ventilation of ordinary farm buildings or ruralschool houses or churches. One of the mistakes most oftenmade in installing a ventilation system in barns is illus-trated in Fi«_r. 2). where a one-story barn is provid<d with 52 Ventilation. short ventilating flues which, because they are short, have alow efficiency and then this efficiency is still further reducedby covering the outlet with closely louvred shelters whi(ihmaterially diminish the effect of the wind in aiding venti-lation. r- Fig. 25.—Low ventilating flues having their effici
Size: 1801px × 1388px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectventilation, bookyear
