Document Lg9wZpqdbwGx94xZYdybgb9Gd

Ventilators The John Call Company VENTILATING SPECIALISTS 128 North Franklin Streep PHILADELPHIA, PA. BRANCHES IN ALL PRINCIPAL CITIES ROOF VENTILATORS AND WINDOW VENTILATORS tjberty^- Products The Liberty Ventilator. A roof ventilator for any type building or enclosure, such as Schools, Hospitals, Foun dries, Barns, Churches, Armories, Residences and similar structures. Also highly efficient for increasing draft in chimneys, flues, stacks, etc. Back drafts impossible, regardless of wind conditions. Rain or snow cannot penetrate. No moving parts to ra'ttle or require attention. Substantially and' staunchly built of any metal desired; Large stocks for prompt shipment. The Pul-Air Impingement Ventilator The Pul~Air Ventilator A good practical roof ventilator of the mushroom type, consisting of a doublecone top. Scientific storm band and im pingement band. Made in every size and of any metal. Strongly built. Large stocks carried. Will not back draft; maximum of free areas. THE LIBERTY VENTILATOR LIBERTY VENTILATOR Good architectural lines and symmetry ANATOMY OF LIBERTY VENTILATOR-- shewing Positive venturi action. White arrows^ indi~ cate outside winds. Black arrows foul air being pulled out Embraces all four principles of scientific ventilation:--1st, Impingement; 2nd, Positive and Negative sides of Ventilators; 3rd, Siphonage; 4th, Stack Action. A positive and complete venturi action. The Liberty Ventilator combines the principles of siphonage and air impingement. This in conjunction with the positive and negative sides of the ventilator creates a vacuum to which the air is naturally sucked regardless of the direction of the wind. Stack action, also, is so accommodated as to accelerate this movement. The free areas of the Liberty ventilator create no resistant constant. Send for copy of tests conducted by Carnegie Institute of Technology, and Massachusetts Institute of Technology. Mechanical and Engineering Data, Service Talks, Catalogues and Prices gladly sent on request. 554 Ventilators Royal Ventilator Company 415 Locust Street PHILADELPHIA, PA. Manufacturers of Ventilators and Exhaust Heads PRODUCTS: Royal Double Cone Ventilators of Galvanized Steel, Copper, Toncan Metal, Armco Iron, Etc., Glass Top Ventilators; Rectangular and Square i Ventilators; Fire-retarding Ventilators; Smoke-jack and Combination Ventilators; Insect and Bird-proof Ventilators; Steam Exhaust Heads. The Royal Double Cone Ventilator is designed to produce maximum ventilating efficiency. The Royal will give effective ventilation during adverse weather conditions; at all times an upward draft is maintained. Schools, hospitals, theatres, also fac tories, power-houses and foundries are among the types of buildings effectively ventilated with the Royal. The Royal is 100 per cent efficient. The principles that have made Royals superior: Patented Trade Mark Reg. U. S. Pat. Office 1. Double Tapered Outer Frus tums.--The wind pressure de flected over and under the edges of the frustums constitutes a strong up draft. 2. The Inverted Cone.--Placed di rectly in the center of ascending air, which on striking it is deflected directly upward and outward. 3. Radiating Ribs in the Cones.-- These prevent the air from swirl- `'ROYAL" Rectangular Ventilators, made to any desired size, ing around, and also add to the Glass or Metal Top, for Schools, Mills, etc. firm construction. 4. Strenght and Rigidity.--Edgewise galvanized malleable iron braces, lapped seams, wired edges. 5. Graceful Design.--Efficient, Faultless, Storm-proof. Send for Catalogue. Dimensions and Technical Information Vent Size Inches 10 12 14 16 18 20 24 28 30 34 . 36 40 42 . 46 54 60 66 72 ^Exhaust _per Minute. . Wind. 5 Miles Per Hour Temperature Difference in Building and Outside 0 141 159 306 388 490 606 874 1186 1364 1765 1961 2424 2673 3489 5414 6665 7851 10682 20 186 417 426 512 832 9/1 1373 2080 2390 2987 3361 41 it 4680 5987 8304 9721 13346 16910 Height Inches 12 13 15 17 16 21 24 26 26 23 28 34 34 39 42 47 52 54 Outside Diameter Inches Area 16 78 19 113 22 164 26 201 29 255 31 314 39 453 45 615 45 707 50 908 56 J0I7 61 1257 68 1386 75 1809 84 - - 2390 94 2807 103 3504 108 | 4071 Cauge Iron Ounces of Copper 24 24 24 24 24 24 22 20 20 20 20 20 18 and 20 16 and 20 18 and 20 18 18 18 16 16 16 16 16 16 18 18 18 18 "18 20 20 20 20 24 24 24 555