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1947-48 Theatre Catalog, 6th Edition, Page 424 (410)

1947-48 Theatre Catalog, 6th Edition
1947-48 Theatre Catalog
1947-48 Theatre Catalog, 6th Edition, Page 424
Page 424

1947-48 Theatre Catalog, 6th Edition, Page 424

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FIGURE 4*The experimental house unit was constructed on a root in Boulder, Colorado. Lying on the slope of the roof are 16 supports constructed of sz-inch lumber. supported and separated by iron strips In the sides of these

which also act as supports for the cover glass.

During the heating season, thegas meters in the test house and in the identical adjacent house were read each month and compared in order to determine the fuel saving effected by the solar unit. The gas consumptions in the test house before and after the installation of the solar unit were also compared on a degree-day basis.


One of the most important results of the entire investigation is the proof of the workability of the principle advanced by K. W. Miller (in a memorandum dated July 12, 1943, to Ohice of Production Research and Development, War Production Board). Although experimental heat recovery efiiciencies and exit air temperatures are not as high as predicted theoretically, the results indicate that solar energy can be used to heat air to temperatures in excess of 200 degrees Fahrenheit and that over-all heat recovery efficiencies of at least 35 percent of total can be secured.

Of perhaps the greatest practical signihcance is the fact that a solar heating unit was constructed and installed in a typical small home; was provided with completely automatic controls; was tied in with the normal heating system; and was operated satisfactorily throughout one complete Winter. A fuel saving of approximately 20 percent was realized.

Other important specific results involve the details of construction and operation of the equipment. Such factors as the use of two-thirds overlap of plates

painted oneethird black on the upper surface, 14-inch spacing between plates, plate lengths of 3 to 4 feet, support of plates on strips driven into wood section sides, and method of supporting cover plates are practical results in building and testing the equipment. The recirculation of house air through the unit, maintenance of air rate at the optimum value, available temperature of air, heating load carryable, equalization of temperature in the various sections are useful results obtained from operating studies of the equipment.

The results indicate that there are good future possibilities for utilization of this solar heating principle, and that further work to develop the apparatus commercially marketable units is justified. Indications are that the owner of a moderate-size house could feasibly have solar equipment installed which would save two-thirds of his winter fuel bill in a climate having considerable winter sunshine, but rather large heating requirements. The relatively low cost and simplicity of construction of the equipment are probably its greatest ad vantages; and, since the efficiencies are comparable to those secured with flatplate collectors heating water, and much greater than those obtained with simple large south windows, it is felt that commercial development may be possible as soon as the few remaining problems have been solved.

It is to be realized that all data, calculations, and results have been made at one locationeBoulder, Colorado*40 de

pieces are cut appropriate slots into which are driven narrow strips of composition board so that they will support the glass plates in their proper relation. At the end of each strip is fastened a small wood block which prevents the glass plates from sliding down the roof. Snow is no problem.

grees 0 minutes north latitude, 105 degrees 16 minutes west longitude, 5,428 feet elevation. All the results in general -and those of the house operation in particularscannot be applied to other locations without discretion. Certain generalizations, however, can be made. Thus, in locations in which the solar radiation received is greater than in Boulder (because of lower latitude, for example) or heating equipment is less (because of higher winter temperature), either the fraction of the heating load carryable by a solar unit of the same size would be greater in the other locae tion, or a collector to carry the same load could be smaller or tilted at a lower angle. For prediction of size of collector needed to carry a certain heating load in another location, data on latitude, solar radiation, winter temperatures, and house-heating requirements are necessary.

Results obtained with the collector alone, as in the case of the laboratory runs, can be applied more readily to other locations; and comparable per formance can be expected if consideration is given to the different angle at which the sun strikes the collector at the different latitude. Thus, for the same projected area of collector, and equivalent cloudiness, heat-recovery efficiencies should be very similar at the same air rates, even in widely different locations.

It is probable that, although the conditions for utilizing solar energy at Boulder, Colorado, are considered to be good, they are close to the severity beyond

1947-48 Theatre Catalog, 6th Edition, Page 424