140 



The Rorists^ Review 



Mabch 2, 1922 



Greenhouse Heating 



Subscribers are invited to write the 

 editor of this department with regard to 

 any details of greenhouse heating that 

 are not understood. When information 

 is desired regarding the capacity of boil- 

 ers, or the amount of radiation required 

 for a greenhouse, the needed tempera- 

 tures should be stated in the inquiry, as 

 well as the amount of glass in the side 

 walls, and the dimensions and general 

 arrangement of the greenhouses. It is 

 often helpful, also, to have a sketch 

 showing the location of the houses. 



PEODUCING CIRCULATION. 



We operate two Foley greenhouses, 

 20x110 feet each, and heat them with 

 hot water. The boilers are the Ameri- 

 can No. 36-5. It is almost impossible 

 to keep the temperature up to that re- 

 quired for our purposes and we find 

 that the water in the boiler will boil 

 over before the pipes in the greenhouse 

 get warm throughout one-half of their 

 length. It is our belief that this condi- 

 tion arises from the fact that the cir- 

 culation is sluggish, but we should like 

 to have your opinion on the matter. 

 We have been advised that circulating 

 pumps are the things we need to ob- 

 viate this difficulty. How can we 

 remedy this condition? 



O. H. W.— N. D. 



Nothing in the above statement af- 

 fords any idea of the cause of the 

 trouble. An electric pump would un- 

 doubtedly improve the circulation, but 

 without knowing more regarding the 

 arrangement of the radiation, it is im- 

 possible to state absolutely that this 

 would correct the difficulty. The Union 

 Pump Works, Battle Creek, Mich., 

 makes a specialty of pumps for this 

 purpose. 



In most cases a sluggish circulation 

 is caused by using too small flow pipes, 

 or by having the returns below the top 

 of the boiler. To maintain 50 to 55 

 degrees when the outside temperature 

 is 30 degrees below zero, in a house 

 20x110 feet, with thirty inches of glass 

 in the side walls, it would be advis- 

 able to use five 2V^-inch overhead flow 

 pipes and fifteen 2-inch returns. For 

 two such houses a boiler rated for 4,- 

 000 square feet of hot water radiation 

 will be needed for use with soft coal. 

 The circulation will be greatly improved 

 if the flow pipes are overhead and run 

 downhill, and if the lower ends of the 

 returns are above the top of the boiler. 



The use of a mercury generator, or 

 some similar method of securing a closed 

 system, thus placing the water in the 

 system under pressure, will not only 

 improve the circulation, but will, in a 

 measure, correct troubles due to a defi- 

 ciency in the number or the size of the 

 flow pipes, and will also increase the 

 efficiency of the return coils. 



DETERMINING BOILER CAPACITY. 



Will you kindly instruct me as to 

 how the capacity of a boiler is deter- 

 mined? W. H. B. — 0. 



The cajjaeity of a boiler varies with 

 the t_vpe of boiler in use, the quality of 

 the fuel burned and the height and diam- 

 eter of the chimney. It is, therefore, 

 impossible to give any exact rule in an- 

 swer to your question. TTowovor, a hori- 



Uncle Sam's Greenhouses 



When Uncle Sam builds a greenhouse he is mighty 

 particular about how it is built and what goes into 

 it. He employs the best brains available to develop 

 and maintain the departments of the government 

 where botanical and horticultural research and 

 experiments are conducted. 



Merit alone is responsible for the selection of 

 Kroeschell Boilers for heating the Conservatories of 

 the President, the Plant Introduction Garden of the 

 Department of Agriculture, the U. S. Propagating 

 Gardens and many other government houses all 

 over the country, too numerous to mention in 

 this space. 



Where there are rigid requirements, Kroeschell 

 Boilers are invariably picked to fulfill them, because 

 a highly successful service performed for years has 

 made Kroeschell Boilers stand far above all other 

 boilers. 



Install a Kroeschell Boiler in your greenhouses, 

 and it will not be long before you realize why mil- 

 lions upon millions of feet of glass are heated by 

 Kroeschell Boilers. 



We Can Ship Any 

 Size Boiler At Once 



Telesrraph or Telephone 

 your order at our expense. 

 Long distance phone, 

 Superior 8680. Ask for 

 greenhouse department. 



KROESCHELL BROS. CO. 



H 



to' 



K 

 I 



444 W. ERIE ST., 



CHICAGO, ILL. 



