Document Z8ja8BXXyZQMvQGdrjyDy2Ne8

Heating Systems steam rT'sph'ric C. A. Dunham Company Administrative and General Offices 450 E. Ohio Street, Chicago, HI. Factories: Marshalltown, Iowa; Michigan City, Ind.; Toronto, Canada; London, England C. A. Dunham Co.. Ltd., 1523 Davenport Road, Toronto, Ont., Canada C. A. Dunham Co., Ltd., (Of the United Kingdom) Morden Road, London, S.W. 19,, England See "Dunham Heating Service'' in local telephone directory in all principal cities. The accumulated experience of the entire Dunham Organization is put at the disposal of the Heating Ventilating and Air Conditioning Engineer. This cooperation is available for Modernization Work, as well as for new construction in industrial, commercial, housing and other projects. The Dunham Sub-atmospheric Steam Heating System maintains desirable tempera tures throughout a building by automatic cdntrol of both steam temperature and steam volume. The system is a simple two-pipe system in which all the essentials of circulation, distribution and control are co-ordinated. Control of the temperature of the steam is accomplished by controlling the pressure or vacuum of the steam in the supply piping and radiators to balance exactly the heat input with building-heat-loss. The Dunham Sub-atmospheric Sys tem distributes a varying supply of heat equally, automatically and continuously through the heated space. Desirable building temperatures are automatically maintained under varying weather con ditions. A positive continuous circulation is maintained as a fundamental function of the system. This maintains unusually constant temperature levels throughout the building. The Control is Fully Automatic. The RT (Resistance Thermometer) Con trol Equipment, which is an integral part of the System, is fully automatic. Begin ning with a maximum radiator heat output obtained by steam circulation at a pressure of 2 pounds and a temperature of 218 F or more as required, the output is progres sively reduced according to the demands of the weather, by a reduction in the rate of steam admission to the system, which automatically causes a reduction in steam pressure and temperature so that steam may be circulated at varying temperatures down to about 133 F. ... Further reduction in heat-output is obtained by partial filling of radiators with sub-atmospheric steani until the point is reached at which the need for heat ceases and the supply of steam is completely shut off. The distribution of the steam supply is automatically main tained under all variations in supply by the co-ordinated functioning of the Traps, Pump, Differential Controller and Regu lating Orifices at radiator inlets. thermostat control panel 970 C. A. Dunham Company Heating Systems Sub-Atmospheric Steam DUNHAM UNIT HEATERS Type C--A specially designed heater for Industrial and commercial structures. Designed for moving a large volume of heated air at low temperature down to working levels making possible a heated air stream discharging directly floorward. 10 sizes, 3 types of outlet diffusers, capacities 100 to 2000 sq ft EDR. Type R--13 standard sizes. Capacities from 381 to 3355 sq ft EDR. Also in suspended type. Both types either direct connected or belt drive. Type V--36 sizes. Capacities from 95 to 1100 sq ft EDR. Type D--12 sizes. Capacities from 558 to 2360 sq ft EDR. Type F--12 sizes. Capacities 1074 to 4550 sq ft EDR. Type R Type V Type D Type F DUNHAM PUMPS Tested and Rated with A.S.H.V.E. Code and Code of Vacuum Return Line Heating Pump Manufacturers* Section of Hydraulic Institute. Vacuum Pumps Type VRD--Designed for use with Dunham Subatmospheric Steam Heating. Capable of maintaining whole systems under vacuums as high as 25 in. Built in 9 sizes. Capacities 2500 to 65,000 sq ft EDR. Type VR--Meets all code tests for air and simultaneous' air and water handling capacities. No moving parts or close clearances in exhauster unit. Built in 11 sizes. Capacities 2500 to 150,000 sq ft EDR. Condensation Pumps Provide automatic return of water of condensation to boilers for gravity systems or steam process equipment. Pump and motor assembled on rigid cast iron base. Bronze fitted centrifugal pump has non-corrosive shaft. Enclosed type Impellor. Liberal size ball bearings. Receiver tank equipped with float switch and push button starting switch with over-load protection. Type CH-B--66 sizes of varying capacities and dis- Type VR charge pressures. Capacities 2000 to 50,000 sq ft EDR; 60 cycle d.c. or a.c. 1750rpm;25or50cyclea.c., 1450 rpm. Type CHH-B--49 sizes of varying capacities and discharge pressures. Capacities 2000 to 50,000 sq ft EDR; 60cycled.c. ora.c. 3450 rpm;25or 50cyclea.c., 2850rpm. Type CV---48 sizes of varying capacities and discharge pressure. Capacities 2000 to 25,000 sq ft EDR. Duplex Unit Type CH or CHH Model B Single Unit Type CH or CHH - Model B Type CHHB 971 Type CV