By limiting turndown to 5:1, Patterson-Kelley can maintain the dewpoint as high as possible, which allows for greater condensation.

The boilers utilize a hydrophobic-coated, finned stainless steel heat exchanger to work in concert with the existing high-efficiency cast-iron heat exchanger.

The Aspen and Aspen Light commercial condensing boilers feature a 10:1 turndown ratio, efficiencies of up to 96 percent AFUE, and boast low emissions. With a stainless steel, vertical, firetube heat exchanger, the Aspen line includes seven sizes between 85-399 MBtuh, with a 155-MBtuh combi unit available.

The Free Flex Ultra-High Efficiency Commercial Condensing Boiler offers a thermal efficiency of 95 percent and features Bryan’s weld-free design. The Free Flex permits field access to the heat exchanger for cleaning and an unprecedented tube replacement.

The ClearFire-CE (CFC-E) condensing boiler can achieve up to 99 percent efficiency due to its enhanced AluFer^® firetube heat exchanger and dual temperature returns.

For large residential or light commercial applications requiring a multiple boiler setup, the Evergreen provides ZoneStacking™— the capability to operate 24 zones without an additional external third-party control.

BSRIA Inc. reports that from 2012 to 2016, sales of condensing boilers grew from 30 percent of the commercial market to over 60 percent, and that number is expected to climb to 80 percent by next year.