Bryan Steam has introduced the HE-AB Series of forced-draft gas-fired “Flexible Water Tube” water boilers with a guaranteed efficiency of 85%. The high-combustion efficiency results from a uniquely designed integrated extended surface heat extractor. These boilers feature 7 sq. ft. of heating surface per boiler horsepower. They operate at normal operating temperatures without the need to provide for the expense or complications of special venting and/or condensing material. The HE-AB Series is available in six models with inputs from 900 to 3,000 mbh.