Fig. 129.
Fig. 130.
The heat from steam is almost exactly identical with that from hot water, and few can distinguish between the two systems when properly erected.
They are both healthful, economical and satisfactory methods of warming. They give no gas, dust nor smoke; are automatically regulated, and therefore allow of an even and constant temperature throughout the house, whatever be the condition of the weather outside.
The circulation of the steam through the warming pipes is effected in an almost unlimited variety of ways, and the cause producing the circulation throughout the pipes of the warming apparatus is solely the difference of pressure which results from the more or less rapid condensation of the steam in contact with the radiating surfaces.
A partial vacuum is formed by this difference of pressure within the radiating portions of the apparatus, and the column of steam or of water equivalent to this diminution of pressure, constitutes the effective head producing the flow of steam from the boiler, at the same time the return current of condensed water is determined by the downward inclination of the pipes for the return course.
Points Relating to Steam Heating.
No two pipes should discharge into a T from opposite directions, thus retarding the motion of both or one of the returning currents. This is called “butting” and is one of the most vexatious things to encounter in pipe fitting.