. Florists' review [microform]. Floriculture. 174 The Florists^ Review Dbcbmbkb 15, 1921 of air valves, but avoid the bother of frequently testing them to make sure that the system is free from air. The principal advantage of running the flow pipe downhill, after carrying it to the highest point in the system as quickly as possible, is that the circula- tion of the water in a hot water system depends upon the fact that cold water is heavier than hot water, and the greater weight of the cold water re- sults in its traveling back through the returns, forcing the hot and lighter water in the boil
. Florists' review [microform]. Floriculture. 174 The Florists^ Review Dbcbmbkb 15, 1921 of air valves, but avoid the bother of frequently testing them to make sure that the system is free from air. The principal advantage of running the flow pipe downhill, after carrying it to the highest point in the system as quickly as possible, is that the circula- tion of the water in a hot water system depends upon the fact that cold water is heavier than hot water, and the greater weight of the cold water re- sults in its traveling back through the returns, forcing the hot and lighter water in the boiler out into the flow pipes. The hot water does not rise nat- urally in the pipes, except as it is pushed out of the way by the heavier cold water. A hot water system is something like a wheel, supported so that it will swing freely. If of the same weight at all points, it will remain stationary, but if any portion of the wheel has more weight than the remainder of the wheel, it will revolve until the heaviest portion is at the bottom. In a hot water system, the water in the pipes between the highest point of the system and the boiler on one side, and the water between the highest point and the boiler on the other side, will be balanced against each other. Everything else being equal, the tendency to circu- late will be in proportion to the temper- ature of the water, which will really de- termine the weight of the water on the opposite sides of the highest point in the system. So far as the present ques- tion is concerned, the size and length of the pipes makes no difference, although the higher the point at which the water cools, the greater will be the tendency to circulate. Now to return to the point in question, "Why is it better to have the highest point in the system near the heater?" The nearer it is to the heater, the less opportunity for the water to cool; if the flow runs uphill through the house, the amount of cooling will be in- creased and, as this will t
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Keywords: ., bookcentury1900, bookdecad, booksubjectfloriculture, bookyear1912
