All fuel-burning furnaces have a primary heat exchanger. But high-efficiency gas furnaces also have a secondary one, which typically consists of an array of metal tubes. Hot air from the primary ...

NANO Nuclear Energy (NNE) announced that it has contracted with Thermal Engineering International, a Babcock Power company, to advance the ...

Instead of a flue, they utilize a secondary heat exchanger, basically a set of coils where combustion gases cool and condense. Condensation produces heat, which combines with the heat from the ...