Secondary heat exchanger said to save 15%.

PEACHTREE CITY, Ga.--Anderson 2000 Inc. here has begun marketing a line of condensing heat exchangers designed for secondary, low-temperature heat recovery in boilers and process furnaces, according to president Jack Brady.

The Subdew condensing heat exchanger is installed next to the boiler, and routes hot exhaust gases through a tubular heat exchange box, Brady said. In the process, heat from the exhaust gases is transferred to either liquid or air that is circulated through the tubes, he explained.

After recovering the heat, the air or liquid in the tubes can be used to preheat incoming boiler combustion air, makeup water or domestic hot water, he said. The tubes can also carry process chemical streams that require some …