This section is from the book "Modern Buildings, Their Planning, Construction And Equipment Vol3", by G. A. T. Middleton. Also available from Amazon: Modern Buildings.
The most common form of gas fire is that in which a burner is fitted to an existing grate, and the firing space filled up with asbestos or coral lumps. This is a very good form, but although the first cost is less than a specially made complete fire, the consumption of gas is higher to obtain the same result, and it will be found that the larger outlay in the beginning is generally cheaper in the end.
A point to be borne in mind in a fire of this kind is that the flue of the fireplace must be nearly closed, and only a small outlet left for the fumes, or there will be a great wastage of gas. A fire-brick back should be placed in the stove and the burner kept well to the front of the fire, to obtain the best effects. These types of burners are shown in Fig. 112, while a section of this sort of fire showing the arrangement of firebricks, etc., is illustrated in Fig. 113. A good example of a tubular stove is shown in Fig. 114, the section showing the arrangement of flues for the heating and discharge of the warmed air.
A stove suitable for use in shops, entrance halls, offices, etc., where it is not possible to provide a flue, is shown in Fig. 115, "The Brighton." The products of combustion are condensed. A vessel is fitted under the stove which receives the product, and this should be emptied daily to be efficient. This is called a condensing stove, and there are several others of a similar character.
A stove now being much used is the "Omega" (Fig. 116), which requires neither flue nor condensing chamber, the makers claiming for it that by the arrangement of the flues the fumes are completely sterilised and purified before being discharged into the room. This stove is portable, and can be supplied by special gas-proof flexible metallic tubes; and it may be stated here that rubber tubes should never be used either for such stoves or for kettle boilers, etc. The principles and construction can be easily understood from the section.
Another excellent application of gas for heating purposes is shown in the gas-heated steam radiator. This is to all appearances an ordinary radiator, into which is poured a small quantity of water by means of a valve and glass tube, as shown in diagram (Fig. 117), it being usual to keep the water level about the centre of the gauge glass. Gas heat is then applied to the water chamber, steam being thus generated, and the radiator is very quickly and well heated. This is really an excellent heater, and can be used without flues in any position that can be reached by a gas pipe. On the same principle as the last example is the condensing gas radiator. This is very similar to the gas steam radiator, but there is no water in it at all, a condensing chamber being formed in the bottom to receive the products of combustion. This is also a good heater, with the advantage that there is no danger of the radiator being damaged by a careless person neglecting to see that the water vessel is filled, as is possible in the case of the gas steam radiator. An illustration of this is given in Fig. 118.
In conclusion, attention may be called to the great importance of testing the whole of the pipes and fittings in a building before they are plastered over or otherwise covered up. This is very frequently neglected by smaller tradesmen, but the expense involved in the purchase of a testing apparatus will frequently be saved over and over again. The writer has in his mind instances where this precaution has been neglected, and the expense and trouble involved in remedying the defects in these cases are oftentimes most serious.