Document bNOz0jkq7kLgZLb8vyRRv83D

American Society of Heating and Ventilating Engineers Guide, 1925-26 Where round domestic boilers are contemplated, those with a maximum number of horizontal, water sections above the fire-box are to be pre ferred. In selecting burner sizes the total load imposed upon the boiler and thence upon the burner should be carefully determined. This load should be determined in accordance with the method for determining the load on any boiler as outlined in preceding chapters. The same allowance for hot water heaters should be made as for ordinary boiler practice and the same precaution should be followed in insulating the boiler and piping. Draft is a matter of importance, since the quantity of air introduced by the very essential motor driven burner fan, must have adequate oppor tunity to pass freely into the stack. The standard practice of assigning an individual flue to the heating boiler should be strictly adhered to. Oil burners with their frequent periods of idleness, and the consequent elimination of needless fuel consumption, do not always impart sufficient heat to ordinary water coils in the fire-pot of heating boilers. Where vapor or steam is used, any of the boiler water-heating units that connect into the boiler below the water-line, thus heating the storage tank, should be used. In hot water heating plants, larger coils are necessary. In studying the burner equipment itself, attention should be given to the'stability of the burner manufacturer and that of his local distributor. The reputation of the burner in past performance is of equal importance. The simplicity and quality of the mechanical construction should be studied.and the element of noise, must be given attention. A burner listed as standard by the Underwriters' Laboratories, may be considered as having been built-up standards. 162 Chapter XI GAS HEATING By W. E. Stark, Non-Member THE increase in the use of gas for space heating has been a. great stimulus to the development of highly efficient gas burning appli ances. Gas-burning heating installations as the sole source of heat for residences, factories, and public buildings (formerly limited to those localities where there was an abundant supply of cheap gas) are taking a more prominent place in coal-burning regions. Gas-burning heating appliances present an opportunity for the realiza tion of nearly ideal efficiencies in combustion and heat transmission. Full advantage must, however, be taken of the inherent efficiency of such appliances and every effort made to retain this efficiency, for it is only on this basis that gas can compete with coal. TYPES OF GAS HEATING APPLIANCES Gas-burning heating appliances may be classified as those for heating individual rooms; and central heating plants, heating an entire residence or other building. Each classification may be subdivided as follows: 1. Room Heaters a Reflector Heaters (luminous flame) b Radiant Heaters (blue flame) c Gas Logs (blue flame) d Tubular and Cylindrical Radiators (a) Floor Furnaces e Gas Fired.Steam Radiators (a) Bungalow type hot water systems ^ . 2. Central Heating plants .' a Warm Air Furances . ^ b Steam Heating plants............ D c Water Heating plants COMBUSTION OF GAS lit the above classification it will be seen that some heaters are desig nated as luminous flame or blue flame. This distinction conies from the type of burner used. Gas burners are of two general types: Luminous flame burners, and the. more widely used Bunsen or blue flame type. Each type of flame has its.own field of usefulness; and if combustion, is complete, and the flame properly applied, each will deliver the same amount of heat from a given quantity of gas. Gas requires for complete combustion air in the proportion of about 1 cu. ft. for each 110 B.t.u. of gross heat value. The two' flames differ in the manner in which this air is supplied for combustion. If gas is forced directly into the atmosphere through a small hole, the air required for combustion is drawn into the 163