Indirect fired systems work at high water temperatures (as high as 90°C). The heat is then transferred to the sanitary water via a heat exchanger. These systems are characterized by a considerably higher gas consumption than the direct fired A.O. Smith systems.  

The graph (below) shows that this achieves gas economies that can grow to as much as 50% of the total gas consumption. Thanks to the unique design of our heat exchangers and intelligent control modules, maximum efficiency is accomplished with a minimum energy consumption.

A.O. Smith condensing gas and solar/gas water heaters have a beneficial effect on your EPC calculation when designing your building and making decisions about your installation requirements. Our systems already fulfill the strictest requirements in the area of upcoming EUP Ecodesign regulations and can be found in the categories with the highest possible energy labeling.