A boiler economizer is a heat exchanger device that captures the "lost or waste heat" from the boiler's hot stack gas.

The economizer typically transfers this waste heat to the boiler's feed-water or return water circuit, but it can also be used to heat domestic water or other process fluids.

Capturing this normally lost heat reduces the overall fuel requirements for the boiler.

Less fuel equates to money saved as well as fewer emissions - since the boiler now operates at a higher efficiency.

This is possible because the boiler feed-water or return water is pre-heated by the economizer therefore the boilers main heating circuit does not need to provide as much heat to produce a given output quantity of steam or hot water.

Again fuel savings are the result. Boiler economizers improve a boiler's efficiency by extracting heat from the flue gases discharged.

We have heat exchanger design software which Guentner and Cabero are using,  Vrcooler offers 

tailor-made heating and cooling unit.