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1947-48 Theatre Catalog, 6th Edition, Page 432 (418)

1947-48 Theatre Catalog, 6th Edition
1947-48 Theatre Catalog
1947-48 Theatre Catalog, 6th Edition, Page 432
Page 432

1947-48 Theatre Catalog, 6th Edition, Page 432

THE AIBTOPIA MODEL 500 is seen (above) with the panels removed to show the blower, motors, coil heaters, electric panel, and compressor motors. In the other picture (below) the same Model 500 shows tans at the top, with the coil and desuperheut coil with humidifier iust below. The compressor is shown at the bottom. Motor does not show. Airtopia units are manufactured by Drayer-Hcmson, Inc.

give the summer cooling effect. In this connection, the use of radiant heating, with relatively low temperature hot water flowing through pipes laid in the floor, or baseboard molding ducts, would appear to have interesting possibilities.

Operational Costs

Electric space heaters, of course, have long been familiar. These units involve resistance heating, which requires a great deal of electric energy flowing through the coil. Under present costs of delivering electricity to our homes, they are expensive to operate; for the amount of heat delivered they cannot begin to compete with coal or oil, or even gas.

The heat pump, however, overcomes the cost handicap of straight electric heating. It does this by having what is known as a ttcoefficient of performance" of from 3 to 5. This means that it delivers from 3 to 5 times as much heat energy as it requires in the form of electric energy for its operation. This is based on the fact that the electric energy used in the heat pumps operation is itself given up in the form of heat and, at the same time, a large amount of additional heat is obtained from the outside source, the air, ground water, or the earth.

This characteristic of the heat pump is what gives it its basic competitive advantage. Sporn estimated that an average well-built, 6-room house in the vicinity of Pittsburgh, in a typical year, would require approximately 8,900 kilowatt hours for heating and about 2,000 kilowatt hours for cooling in the summer. At a rate of 11/2 cents a kilowatt hour, this would mean a winterls heating bill of about $135 and a cost of about $30 for cooling in the hot months.

In the fall of 1946, A. C. Crandall, vice-president of Indianapolis Power and Light Company, reported that in a test conducted during the 1945-46 heating season, in a 5-room house in Indianapolis, a heat pump installation consumed 6,357 kilowatt hours, of which 6,013 kilowatt hours were used by the motor driving the compressor, and 344 kilowatt hours by the blower fan.


There are at the present time at. least three concerns manufacturing heat pumps on a commercial basis.


The Muncie Gear Works, Inc., of Muncie, Indiana, is turning out a unit under the trade name Marvair. M. M. Smith, vice-president of the company, recently told the writer that they have had Marvairs operating in Muncie for three seasons. One of these units has been in a private home and the total electric input per heating season was 8,825 kilowatt hours. The total degree days for this area at (55 was 5,278. However, he pointed out that the home was maintained at 78 degrees night and day, which would make the degree days as applied to home temperature come to 6,318. The Btu. load of this home was approximately 50,000 Btu. an hour 1055 at zero, and from these figures he said that their formula of operation cost was one kilowatt hour per degree day of 410,000 Btu. load.

The Marvair is a ground-to-air utiliz THEATRE CATALOG 1947-48

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1947-48 Theatre Catalog, 6th Edition, Page 432