While traditional boiler economizers recover sensible heat from a flue gas stream, condensing units go a step further. Each 1,000,000 Btu of methane contains more than 91,000 Btu of water vapor, latent heat that represents 9% of the beginning fuel content. Cooling exhaust gas below its dew point with an E-Tech condensing heat exchanger can recover the bulk of this otherwise wasted energy. Depending upon conditions, it is possible to reach combined combustion efficiencies greater than 96%.