More building owners are asking for geothermal heat pumps (GHPs) and other efficient heating-and-cooling alternatives, boosting demand for skilled workers who know how to assemble all the hydronic components. A union in Chicago has just begun to teach its workers formally on the ups and downs of GHPs. Instructors Paul Chapello (left) and William Wren use 4,000-gallon fish tank to keep geothermal installers in the loop. A nearby ground loop, partially exposed, also is tied into the system. Related Links: As More Buildings Go Geothermal, Project Teams Are Thinking Outside the Borehole Along Came a Spider� Editorial: More Straight Talk
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.