Investigation and Design of a Portable Evaporative Cooler

Citation

Foster, Francis Cecil (1949) Investigation and Design of a Portable Evaporative Cooler. Engineer's thesis, California Institute of Technology. doi:10.7907/vxg2-3a57. https://resolver.caltech.edu/CaltechTHESIS:06042025-180553552

Abstract

The purpose of this thesis is the investigation and design of a portable evaporative cooler.

Preliminary investigation was made by a product survey through present evaporative cooler manufacturers. This survey indicated that the project was physically possible; that it had not as yet been solved in practice; that the manufacturers believed such a cooler would find a large market that they were not reaching, since its channels of distribution would be through appliance dealers, while their present channels were through specialists trained in installation. This divergence of channels of distribution had discouraged the development of such a product.

A tentative design was developed and all the appliance dealers in key cities were circularized with a description of the proposed unit. Their advice and comments were requested. From an analysis of their replies and from the advice of the manufacturers, the final design was developed.

The completed "FROST"* evaporative cooler is an aluminum container, 18 inches long, 8½ inches wide, and 12 inches high. It contains a 1/20 horsepower motor, which turns a single inlet squirrel-cage blower, 5¼ inches in diameter, 3 7/16 inches wide, at 1725 RPM, moving 268 CFM of air. The air passes through a venturi tube, which aspirates the water on to a 4-inch thick wire filter, 9 3/4 inches wide, 5 3/4 inches high, where it is evaporated. The base of the cooler contains a separate pan which holds sufficient water for over 2½ hours use. The filter, venturi, and blower scroll are removable by the user for cleaning.

The unit is made chiefly of aluminum to prevent rust, electrolysis of parts, and for ease of cleaning the filter. It is painted with light grey, metallic-type paint that has a slight greenish tint.

The motor, blower wheel, grills, and filter are standard parts to be purchased. The container, venturi, and water pan to be manufactured to specification.

The estimated manufacturer's cost is $11. The sales price is estimated to be $30. The estimated first-year sales are 14,000 units.

____________________

*Trade name selected for this cooler.

Thesis Files