Document 0gZ27076XgQk4N02E3XEVYmVm
Specialties, Heating
C. A. Dunham Company
General offices: Dunham Bldg., 450 East Ohio St., CHICAGO, ILL.
Factories: Marshalltown, Iowa, Michigan Citt, Indiana and Toronto, Ont., Can.
Special Sales Office, Washington, D.C. (Munsey Bldg.), CoL W. S. RibJet
Eastern Division Offices 101 Park Avenue. New York, N.Y.
Central Division Offices 450 EL Ohio Street, Chicago, III.
Western Division Offices 617 W. 7th Street, Loe Angeles, Calif
Albany, N.Y., 91 State St.
Allentown, Pa., 11 S. 5th St
Baltimore, Md., 218 Water St.
Bangor, Maine, 104 Exchange St.
Boston, Mass., 136 Federal St
Buffalo, N.Y.. 232 Delaware Ave.
Clarksburg, W.Va..
Greensboro,
212 N.C.,
Exponent
Bldg.
915 American Bank Bldg.
SALES OFFICES
EASTERN DIVISION
Greenville, S.C., P. 0. Box 563 Harrisburg, Pa., 2216 N. Fifth St Huntington, WVa., 530 First Hunt
ington National Bank Bldg. Johnstown, Pa., 244 Market St Kingston, Pa.,
302 Kingston Corners Bldg. Newark, N.J., 972 Broad St. New Haven, Conn., 30 Whitney Ave. New York, N.Y., 101 Park Ave.
Philadelphia, Pa., 1500 Walnut St
Pitoburgh, Pa., 3002 Grant Bldg '
Poughkeepsie, N.Y., 38 Fulton Ave Provtobncb R.1., 49 Westminster St. RochesterN: Y.t 972 MercantileBldg. Stracurb, N.Y., 306 0. C. S. B Bld
Trenton, NJ., 219 E. Hanover St
Washington, D.C., 327 Munsev Bldg White Plains N.Y., 199 Mam St
(Bar Bldg.)
CENTRAL DIVISION
Special Sale* Office, 450 Ea*t Ohio Street, Chicago, C. E. Roscoe
Akron, Ohio, 1175 La Croix Ave Atlanta, Ga., 804*Foreyth Bldg. Birmingham. Ala., 1216 Martin Bldg. Chattanooga, Tenn.,
1201-03 Volunteer Bldg. Cheyenne, Wro., 430 Bovd'Bldg. Chicago, III., 450 East Ohio St. Cincinnati, Ohio.
1231 Union Trust Bldg. ' Cleveland, Ohio,
.430 Terminal Tower Bldg. Colorado Springs, Colo.,
1424 EL Platte Ave. Dallas. Texas,
Davenport, Iowa, 305 Security Bldg. Denver. Colo., 414 West Colfax Ave. Dbs Moines, Iowa,
^ 710 Old Colony Bldg. Detroit, Mich , 2988 E. Grand Blvd Duluth. Minn., 316 Glencoe Bldg. Ghand Rapids. Mich.,
1003 Grand. Rapids Trust.Bldg. Houston, Texas, 911 Electric Bldg. Indianapolis, Ind.,
Board of Trade Bldg. Ironwood, Mrcn., 6 Albert Bldg. Joliet, III., P. 0. Box 1086
Kansas Citt, Mo., 615 City Bk. Bldg. . Louisville, Kt., 1342 Starks Bldg. Memphis, Tenn., 355 Madison Ave. Milwaukee, Wb., 901 Empire Bldg. Minneapolis, Minn., 132 So. 10th St. New Orleans, La., 419 Maritime Bldg. Omaha, Neb., 527 Peters Trust Bldg. Peoria,. III., 1303 Peoria Life Bldg.. Quinct, III., 628-638 Jersey St St. Louis, Mo., 3605 Laclede Ave. San Antonio, Texas,
3005 Smith-Young Tower Toledo, Ohio, 1918 Vermont Ave.
408 Dallas National Bank Bldg.
Wichita, Kan., 1100 E. Douglas Ave.
wAtern DIVISION
El Paso, Texas. 401 N. Santa Fe St.
Kalispell, Mont.. Whippe Block Los Angeles, Cauf., 617 W. 7th St.
Portland, Ore., 1000 Buyers Bldg
SaltLake Citt, Utah, 204 DoolyBldg San Francisco, Calif.,
Seattle, Wash., 312 Securities Bldg Spokane. Wash., 614 Peyton Bldg
232 Mosadnock ^ldg.
C. A. Dunham Co., Ltd., 1523-41 Davenport Road, Toronto, 4, Ont., Canada.
Sale* Office*: Calgary, Alta,; Halifax, N.S.; Montreal, Que.; Ottawa, Ont; Quebec, Que., St Johns, Nfld.; Toronto, Ont.; Winnipeg, Man.; Vancouver, B.C.
C. A. Dunham Co., Ltd. (of The United Kingdom) 18 St. Thomas St, S.E. 1. London, England.
_ Agencies: Birmingham, Eng.- Leeds, Eng.; Liveroool Eng.; Newcastle^n-Tyne, Eng.; Glasgow, Scotland; Belfast
Ireland, Pans, Franee; Munich, Germany; Copenhagen. Denmark; Gothenburg, Sweden: Wellington, N.Z.
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HEATING SERVICE
This Service is delivered through over eighty Sales Offices throughout the United States, Canada and the United Kingdom. These Branch and Local sales offices bring Dunham Heating Service as close to your office as your telephone. Consult
your telephone directory for the address of our office in your city. An engineer will counsel with you on any project.
DUNHAM DIFFERENTIAL VACUUM HEATING SYSTEM
Heating with Steam of Variable Temperatures--Cool Steam (133 deg. fahr.) Warm Steam (133 deg. to 212 deg. fahr.); Hot Steam (Above 212 deg. fahr.)
Principles and Design
The principle of the Dunham Differen tial Vacuum Heating System is based on the fundamental laws of heat flow and heat processes. The basis of the theory is briefly
summed up in the statement of its object--
to maintain steady temperatures inside a building throughout the heating season, ir respective of the daily and hourly fluctua tions of the outside weather.
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C. A. Dunham Company
Specialties, Heating
No Complicated Equipment Required
The Differential Vac-
uum Heating System ac complishes this without
any complicated or deli cate equipment, or any
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greater variety of appliances than is used by the ordinary Vacuum Return Line Heating System. No larger or special Boiler is
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required on this system than on any other. Any
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type of Boiler suitable for heating work and
No new principle is used to attain the
of high efficiency can be used.
long sought combination of comfortable
heat, with real economy. The application
Easily Adaptable to Change-over From of the Dunham Appliances which utilize
Existing Vacuum Return
this important principle is the only thing
Line Systems
new. These appliances are attention--com
An ordinary, well-designed, Vacuum Re turn Line System can be changed-over to the Dunham Differential System. Radia tion does not have to be disturbed and in most instances existing piping may be used with only slight changes.
The system uses steam as a heating medium. Steam is supplied at variable temperatures from 133 deg. up to 212 deg. and higher if so required. The 133 deg. temperature corresponds to 25 in. of vacuum (at sea level), and 212 deg. to zero on the gauge. By furnishing steam at this wide range of temperatures, it is possible to vary the heat output of the radiation thus preventing overheating.
pelling and revolutionary. They have made the Dunham Differential Vacuum Heating System the outstanding heating develop ment of the decade.
The temperature of the steam is gov erned by the Dunham control equipment and the Dunham Differential Vacuum Pump, which removes the air from the sys tem, thereby reducing the pressure on the water in the boiler, or causing the steam to expand through Reducing Valves when they are used.
The term 11 Differential" is applicable because a relatively constant differential in pressure between the radiator and. the return is maintained, so that the air and water will constantly flow out of the radia
Based on Bed-Rock Laws of Physics
tors. The steam is induced to completely fill them. Due to this "Differential" com plete circulation is obtained and the radia
This system is simple in design, easy to tors throughout the building are heated
install and very economical in operation. uniformly.
Trie Heat Emitted By A Pad Iatop? Depe:dds On The Ti= mpedaturc Difference BetweenTne Radiator And The Air Of Tme Room.
Heat Emission from Radiation Under Vary
ing Pressure and Tem peratures
The heat given off by the radiator is proportion al to the difference in temperature between the room and the radiator. By varying the tempera ture of the radiator, the building temperature can be kept constant, and the heat given off by the radi ator kept in proportion to
the heat loss from the building. By operating the system at varying de grees of pressure or vac uum the temperature of
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