Power, Heating and Ventilation: Heating and ventilationTechnical Press, 1909 - Heating |
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air supply air valves anemometer arrangement B. T. U. per hour basement boiler building carbonic acid carried cast-iron ceiling cent centrifugal fan chamber check valve cold cold-air computed condensation connected cubic feet diameter diaphragm direct radiation discharge draughts drip ducts efficiency electric engine exhaust steam expansion tank feet of heating feet per minute floor flow furnace given heat loss heating surface heating system height horse power hot-water heating indirect inlet live steam main heater method mixing dampers necessary opening outlet placed pounds pressure proportion pump quantity radiating surface regulated return mains revolutions per minute riser schoolhouse sections shown in Fig sizes smoke pipe space speed square feet square foot stacks sufficient supply and return Table temperature thermostat tion trap usually velocity vent flues ventilation volume of air wall coils warm air water-line watt-hour zero weather
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Page 522 - ... be used for this purpose by providing it with steam connections of sufficient size. In the ordinary form of heater, the feed-water flows through the tubes, and the connections are therefore small, making it necessary to substitute special nozzles of large size when used in the manner here described. When computing the required amount of heating surface in the tubes of a heater, it is customary to assume an efficiency of about 200 BTU per square foot of surface per hour, per degree difference...
Page 408 - Water in the form of vapor, varies greatly with the temperature, and the exposure of the air to open bodies of water. In addition to the above, there are generally present, in variable but exceedingly small quantities, ammonia, sulphuretted hydrogen, sulphuric, sulphurous, nitric and nitrous acids, floating organic and inorganic matter and local impurities. Air also contains ozone which is a peculiarly active form of oxygen, and lately a new constituent called argon has been discovered.
Page 471 - Fig. 60, by substituting another. The mixing damper in this case is placed at the other end of the heater. When it is in its highest position, all of the air must pass through the heater before reaching the register; but when partially lowered, a part of the air passes over the heater, and the result is a mixture of cold and warm air, in proportions depending upon the position of the damper. As the layer of warm air in this case is below the cold air, it tends to rise through it, and a more thorough...
Page 473 - Fig. 65 shows an arrangement for this purpose. When the damper is in the position shown, air will be taken from the room above and be warmed over and over; but, by raising the damper, the supply will be taken from outside. Special care should be taken to ma,ke all mixing dampers tight against air-leakage, else their advantages will be lost.
Page 488 - We have seen that an average cast-iron radiator gives off about 1.7 BTU per hour per square foot of surface per degree difference in temperature between the radiator and the surrounding air, when working under ordinary conditions; and this holds true whether it is filled with steam or water.
Page 442 - ... proper drainage and quietness of operation. Efficiency of Radiators. The efficiency of a radiator, that is, the BTU which it gives off per square foot of surface per hour, depends upon the difference in temperature between the steam in the radiator and the surrounding air, the velocity of the air over the radiator, and the quality of the surface, whether smooth or rough. In ordinary low-pressure heating the first condition is practically constant, but the second varies somewhat with the pattern...
Page 494 - Figs. 91 and 92, the latter form being used where the headroom is limited. The connection from the heating system enters the bottom of the tank, and an open vent pipe is taken from the top. An overflow connected with a sink or drain-pipe should be provided. Connections should be made with the water supply both at the boiler and at the expansion tank, the former to be used when first filling the system, as by this means all air is driven from the bottom upward and is discharged through the vent at...
Page 610 - Sometimes a by-pass damper is attached, so that part of the air will pass through the heater and part around or over it; in this way the proportions of cold and heated air may be so adjusted as to give the desired temperature to the air entering the rooms. These forms of regulation are common where a blower is used for warming a single room, as in the case of a church or hall; but where several rooms are warmed, as in a schoolhouse. it is customary to use the main or primary heater at the blower...
Page 470 - The cold-air duct is brought along the basement ceiling from the inlet window, and connects with the cold-air chamber beneath the heater. The entering air passes up between the sections, and rises through the register above, as shown by the arrows. When the mixing damper is in its lowest position, all air reaching the register must pass through the heater; but if the nnnnnnnn WFIO'T IRON PIPE ** Method of Hanging a Heater below a Wooden Floor.
Page 507 - Flues and Casings. For cleanliness, as well as for obtaining the best results, indirect stacks should be hung at one side of the register or flue receiving the warm air, and the cold-air duct should enter beneath the heater at the other side. A space of at least 10 inches, and preferably 12, should be allowed for the warm air above the stack. The top of the casing should pitch upward toward the warm-air outlet at least an inch in its length. A space of from 8 to 10 inches should be allowed for cold...