116 



The Florists^ Review 



Jolt 14. 1921 



heat in zero weather and heat that does 

 not cool oflE quickly when banking the 

 fire. G. C. N.— N. Y. 



While, of course, it is not possible to 

 secure circulation in a hot water system 

 without heat from the boiler, strictly 

 speaking we should not think of the 

 boiler as pushing water through the 

 pipes. The boiler merely heats the 

 water exposed to its fire surface. This 

 causes the water thus heated to expand, 

 and this heated water is, as a result, 

 lighter in weight than a given amount 

 of water in the pipes which has not 

 been heated. 



In a hot water system, what are 

 known as flow pipes are connected witli 

 the top of the boiler and, after the 

 water is permitted to cool in the vari- 

 ous coils, radiators, etc., it is taken 

 back to the boiler in what are known 

 as return pipes, which are connected 

 near the base. 



The water in the boiler having been 

 heated and expanded, the greater 

 weight of the water in the coils, etc., 

 results in the pushing of the hot water 

 out from the boiler through the flow 

 pipes, and its place is taken by the cold 

 water, which, in turn, is heated and 

 forced out into the system, where it is 

 cooled. 



In a given system, the rapidity of the 

 circulation will be determined by the 

 difference in the weight of the water 

 in the boiler and in the pipes, as far as 

 the highest points in the system, on the 

 one side, and in the remainder of the 

 pipes, coils, and radiators on the other 

 side. The weight will vary inversely 

 with the temperature of the water. 



From this it will be seen that wc 

 should endeavor to keep the water in 

 the flow pipes between the boiler and 

 the highest point in the system as hot 

 as possible, or, in other words, it should 

 be so planned that it will not cool any 

 more than is necessary. This means that 

 we should use main flow pipes of good 

 size; and the highest point in the sys- 

 tem should not be far from the boiler. 

 This, of course, means that the flow 

 pipes running through the houses should 

 slope away from the boiler. 



The cooling of the water in the over- 

 head downhill mains, therefore, is an 

 aid to the circulation. 



The circulation will also vary with 

 tne height of the water above the boiler. 

 From this it will be seen that the best 

 circulation can be secured if all of the 

 pipes are overhead, and the higher they 

 are the better, provided the pipes run 

 downhill. The circulation of water is 

 not unlike the draft of a chimney; the 

 higher the chimney the better the draft. 



While it is not advisable to place all 

 of the heating pipes overhead, the use 

 of overhead flow pipes certainly im- 

 proves the circulation and the higher 

 the returns above the top of the boiler 

 the better, so far as circulation is con- 

 cerned. 



In actual practice, for houses more 

 than fifty feet in length, it is advisable 

 to carry one or more main flow pipes to 

 a point two to four feet below the level 

 of the ridge and connect with the ex- 

 pansion tank. Then run the required 

 niinibor of 2%-inch flow pipes downhill 

 to the farther end of the house and 

 connect them with the coils of 2-ineh 

 return pipes. 



Unless there are more than two and 

 one-half feet of glass in one wall of the 

 house, one could heat the house de- 

 sctibed above by using four 2% -inch 



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I i 



Heat Insurance- 

 How To Get It 



= When winter winds and drifting snow join forces to knock the 



= bottom out of the thermometer you need heat insurance. You 



E want to be absolutely sure that sufficient warmth will be main- 



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E 523 Fisher Avenue Marshalltown, Iowa 



~ -■• Agencies in all principal cities ^^ 



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IMICO 



Hot Water Boilers 



Made by 



Illinois Malleable Iron Co. 



1801-1825 Diversey Boulevard 



CHICAGO 



Are noted for COAL ECONOMY a,nd 

 good results generally '. < 



SEND FOR CATALOGUE 



Mention The Review when voii write. 



flow pipes and eight 2-inch returns. 

 For the growing of roses, ^ve flows and 



eleven return pipes will be needed. 

 For most crops a little bottom heat is 



