An installer works at getting a DDI heat exchanger through a narrow area.

Two wastewater treatment plants in Canada's Niagara region have installed a total of three heat exchangers from DDI Heat Exchangers Inc., Dollard-Des-Ormeaux, Quebec. The application called for the rectangular channeled wide-gap units to be inserted in an especially narrow hatch in narrow corridors, says Erwin Schwartz, DDI president.