Steam Heating

STEAM HEATING.

Another efficient method of heating for country houses, is by direct steam radiation. This consists in circulating steam through radiators or coils placed directly in the rooms and halls to be heated. This may be done under high or low pressure, but the low pressure gravity return system is generally used for horse Beating, a pressure of from two to ten pounds being rated as "low pressure".

Piping. Three systems of piping are used in this form of heating called the "two-pipe system ", the "one-pipe relief system ", and the circulating system". In the two-pipe system the main pipe is taken from the top of the boiler and carried by branches along the cellar ceiling, pitching gradually down until all of the "risers" have been taken off, when it drops down and returns with a slight pitch to the boiler, below the water line. (Fig. 5S.) This is called a "wet" or "sealed" return. Sometimes the return pipes are run overhead and this is called a "dry" return. This dry return is more productive of noise in the pipes than the wet return and is not so often used. In either case one set of pipes is run from the main supply pipe in the cellar to the different radiators and another pipe carries the condensation from the radiators to the return pipe. This requires two sets of pipes, valves, and connections and is more ex pensive than the one-pipe systems which are generally used.

One=Pipe Relief System. In this system the arrangement of the cellar piping is the same as in the "wet" return previously described, but the supply to the radiators consists of but one pipe, taken off from the main supply in the cellar, the steam flowing in, and the condensation draining out, through this single pipe to the main and thence through frequent "chip pipes", to the return pipe, near the cellar floor. (Fig. 59.) If the return pipe in the cellar is run overhead, as in the "dry" return system the drip pipes should be connected to the return main by a loop falling below the return, thus forming a trap and preventing the steam from flowing directly into the return.

One-Pipe Circuit System. In

this system the main supply is carried to the ceiling of the cellar and there makes a complete circuit of the building at a downward pitch and connects again with the boiler below the water line. (Fig. 60.) From this eh-ciliation pipe single risers are taken to the radiators, and the condensation flows back through the same pipes to the circulation pipe, and is carried along with the steam and returned to the boiler. This circu lation pipe should be of large size and with a good pitch all the way.

In all single-pipe systems the piping must be larger than in the double-pipe systems, as the steam and the returning water are flowing through the pipes in opposite di rections at the same time. This

may be obviated by running a single riser to the top of the building and then branching out to supply the different radiators by single pipes run back to the basement. In this case the steam and water flow in the same direction and for large work this is often done.

Valves and Connections.

Careful examination should he made of the valves and pipe connections to see that they are efficient and properly applied. Many styles of valves are available, and only well known or well tested patterns should be allowed. Of air valves for steam radiators the simplest form is the "pet cock", a screw valve operated by hand (Fig. 61), but there are several forms of automatic valves on the market which will allow the escape of cold air from the pipes, but are instantly closed as soon as affected by the hot steam.

This is done by the expansion of a metal part which closes the orifice.

Radiators. The form of steam radiator in general use is the cast iron radiator (Fig. 62). This consists of a series of loops con nected at the bottom. The steam entering at one end forces the air out of the air valve placed about midway of the last section. The two end sections are of the same internal pat terns as the others but are cast with legs.

Pipe radiators (Fig. 63) are often used and, where design is not an object, the use of circu lation coils of piping may be per mitted.

Boilers. Many of the nary types of steam boilers are used for steam heating and in addition to these there is a cast iron sectional boiler which is used for dwelling houses to a great extent. (Fig. 64.) The main thing is to select some well-known type and to see that it is carefully set, with all attachments, which will usually be described in the contracts. This method of direct radiation lacks the advantage of the introduction of fresh air into the house, but, if care is taken to provide for this by other means, it is economical and positive in its action. The main point to be seen is that heater, pipes and radiators are amply large, and that the ators are well placed and supplied by carefully graded pipes, tightly and neatly connected. Cellar pipes should be covered with some of the patented sectional pipe coverings, and radiators and all pipes which are exposed to view may be coated with bronze of a desired color. Where pipes pass through floors or partitions they should be protected by sleeves three-quarters of an inch larger than the pipes, and collars should be neatly placed arouund the pipes at the floor and ceiling, or on each side of the partition,