Applications, Advantages & Highlights

Turn up the heat.

Modern boiler applications call for technology that is innovative, flexible and adaptable. KN Series cast iron boilers were purposefully engineered to live up to today's toughest applications and challenges, providing versatility in boiler system configuration and installation without sacrificing the bottom line.

Hybrid Boiler Systems

In this day and age, the word 'hybrid' gets thrown around often. But what about the terms 'base load' or 'mixed-boiler'? Within the commercial boiler market, the concept behind these configurations is simple, lower the upfront equipment cost of a complete condensing boiler plant by incorporating new units into an existing and less expensive non-condensing boiler plant.

With a hybrid boiler system that combines KN Series condensing boilers within an existing, non-condensing boiler plant, operators are able to meet total BTU requirements while optimizing overall system performance, increasing boiler efficiency under various climate, seasonal and load conditions. By operating during most of the heating season, the condensing KN Series units provide the bulk of the high-efficiency BTU output when loop temperatures are low, while the existing and less-efficient non-condensing units act as supplemental boilers when outdoor temperatures fall and boiler loop temperatures increase.

HeatNet 3.0, an innovative boiler control platform featured on all KN Series boilers, with the option of remote monitoring, provides seamless boiler-to-boiler communication in all applications, including hybrid designs with both high-mass and low-mass units. In addition, HeatNet 3.0 technology optimizes system efficiency by prioritizing the firing rotation of all boilers within the system, whether the units are condensing or non-condensing.

Real World Advantages

All HVAC and building industry professionals have one thing in common: the need for quality equipment, easy installation and great ROI. And with the ever-increasing industry demand for green technologies, it's no wonder that more and more professionals are turning to KN Series by ATH to fulfill all of their boiler application must-haves.

For Architects & Engineers

  • Cast iron construction retains latent heat for maximum efficiencies and is made from recycled materials ' making it a green technology.
  • A simple and compact footprint makes for quick and easy installations.
  • HeatNet 3.0 control software communicates freely with other mechanical room equipment, eliminating the need for third-party building management systems.

Building Owners

  • Fast ROI through quick installation and decreased energy consumption.
  • Annual maintenance and service fees are reduced through a service-friendly design.
  • Cast iron construction and a 21-year thermal shock warranty make for a long-lasting investment.
  • LEED Qualified.


  • Factory-packaged units require minimal piping and field wiring.
  • All units have a small footprint for easier transport.
  • All boiler controls are digital and easily programmed.
  • HeatNet 3.0 boiler control software speeds up diagnostics and installation.
KN Series Efficiency Chart