Warming Buildings by Steam.
The arrangements for warming rooms and buildings by steam are very different from those in which stoves are employed. They are generally such as the following. At a convenient part of the building, and as low as possible, there is placed a close steam-boiler of the ordinary construction. From this boiler a small steam-pipe is carried to the parts of the building which are to be warmed; the pipe being wrapped round with a thick layer of flannel, to prevent the heat from radiating before it arrives at the destined place. Pipes of a larger size are laid round the rooms above the floor, or under a perforated floor, or in any other convenient position. The steam issues into these larger pipes, from the surface of which heat radiates into the room, and thus the steam is condensed into water. Small pipes of lead or tin are provided for convoying the water back into the boiler, a gentle slope being given to all the pipes to facilitate this object. This water, again flowing into the boiler, is again converted into steam, again ascends to the pipes which surround the apartment, again gives out heat to the air of those apartments, and again flows back to the boiler in the form of water. Thus the same supply of water circulates over and over again through the pipes, carrying heat from the fire below to the rooms above. In some cases the steam-pipes in the apartments, instead of being laid round the sides, are grouped together in a compact form, and have an ornamental character imparted to them.
Instead of pipes, the steam is sometimes made to circulate between parallel sheets of copper or iron, in such manner that every sheet of metal shall have steam on one side of it, and air on the other, the air in that position receiving heat from the steam through the metal.