192 



The Country House 



into such drains as may be expedient. It will readily be seen that, as the flow 

 main enters the expansion tank above the outlet into the return, the tank is 



really in the latter. Therefore, in more 

 or less complicated systems the expan- 

 sion tank is often connected with an inde- 

 pendent pipe rising directly from the 

 horizontal return near the heater. It 

 is important to remember, however, that 

 the supply to radiators should be made, 

 as already stated, through the return 

 pipe, or at least not to connect with the 

 flow lower than the point of its turning, 

 and that the nearer the above principles 

 are carried out the better will be the 

 working of the system. 



The one-pipe hot-water system is 

 similar to that of the single-pipe steam, 

 with the difference that the feed and 

 return are effected through separate 

 branches connecting the main with the 

 radiators. 



In both steam and hot water the 

 horizontal pipes have a slight downward 

 pitch in the direction of the flow of the 

 heating medium. 



The mains are commonly covered 

 with felt (often reinforced with asbestos) 

 in their passage through space, when ir 

 is desired that the heat of the pipes 

 shall not suffer from exterior cold or as a guard against fire. For this latter 

 purpose there are several patent sheathings in use. 



The size of the mains decreases and increases in proportion to the supply of 

 the heated vehicle carried by them. In distribution they are supposed to diminish 

 as each sub-heater is supplied; and in return they increase according to the outflow 

 of the radiators. For instance, in low-pressure steam the main flow pipe leaving 

 the boiler to supply 1,000 square feet of radiating surface would be 3 inches in 

 diameter. This would decrease through several fixed sizes to the smallest (ij 

 inches). 



With the steam boiler it is not necessary that it should be below the level of 

 radiators or coils, w r hile with hot water this is important; therefore with a low 

 cellar the problem is easier with steam, provided indirect radiation is used. 



As the low-pressure steam radiator is reckoned at about 210 F. and the low- 

 pressure hot-water radiator at about 140 F., it will be seen that the radiators of 

 the former would be much smaller than the latter for the same amount of work. 

 The hot-water plant is more expensive than steam, but it is claimed that the 

 wear and tear is less than in steam. 



A parlor mantel it Lynn, Mass. The interrupted pediment 

 makes a good top motive, but the mantel bears no relation to 

 the lines of the room 



