In 1936 America was still in the depths of the Great Depression, Roosevelt won re-election over Landon in a landslide, Boulder Dam (later renamed for Hoover) was completed, and in New York City, two engineers, Horace R. Lange and Theodore J. Tottis, started a small business in a new industry. As Air Duct Installation Co., they designed and built commercial ventilating and air-conditioning systems. The glass fiber disposable air filter had been introduced two years earlier by Owens Corning, which was the only manufacturer in the field.
Most commercial air conditioning systems were custom-designed, requiring special-sized filters. Owens Corning’s operations were focused on glass manufacturing and the production of standard-sized furnace filters. Contractors with orders for special filters could not get prompt delivery and sometimes had to put systems into operation without filters. Air Duct Installation Co. began making special-sized filters for themselves and other contractors in the New York area to meet this need. Because Owens Corning would not sell its filter media in bulk, the filters were first made by disassembling standard filters, re-cutting the media and screens, and fabricating new frames to specifications.
As the air conditioning industry expanded, the need for original and replacement special-sized filters grew quickly. Owens Corning finally agreed to sell Lange and Tottis filter media in bulk. They became the first authorized independent fabricators of “Dustop” air filters in the United States. Lange and Tottis formed a new enterprise called “Air Filters Co.” solely for the manufacture and sale of filters.