194 



QREENHOUSE AND WINDOW-GARDEN WORK 



Size of pipes connecting radiating surface and the boiler or heater. 



Various ciiipirical rules hiivo bcoii giv(;n for i^roixjrtioning main- 

 supply ami rolurn pipes, which have i)rov(ul ([uito satisfactory in 

 practice. Cleorgc A. l^abcock gives the following rule, which will be 

 found very satisfactory for greenhouse heating, whether with low- 

 pressure steam or with water: — 



The .liameter of main jiipe leading to the radiating surface should 

 be equal in inches to 0.1 the square root of radiating surface in 

 8(iuare feet. The main pipes should not be less than 1.} inches in 

 diameter, rctv.rn pipes for water heating the same size as mains, and, 

 for steam heating, one size less than mains, but never loss than f inch 

 in diameter. The following table shows the radiating surface sup- 

 plied by various sizes of main pipe. 



(,B) Size or Pipu^ Radiating Surface Supplied 



1 '4 inches 155 square feet 



ly-i inchea 225 square feet 



2 inches 400 square feet 



2^ inches 620 square feet 



3 inches 900 square feet 



'.V -2 inches 1220 s(iuare feet 



4 inches IGOO square feet 



(O Table of dimensions of standard wrought-iron pipe — For steam 

 and water 



1 inch and below, hutt-welded ; proved to 300 pounds per square inch, hydraulic 

 pressure. 



1*4 inch and al)<)vc, lap-welded; proved to 500 pounds per square inch, hy- 

 draulic pressure. 



Table of Standard Sizes 



