CHICAGO — As boiler manufacturers strive for peak efficiency, more are opting for modulating gas condensing configurations. And, not only are these units more efficient, but they’re easier to operate, as many come designed with Internet connectivity and controls. In turn, contractors are enjoying the simplified installation procedures and maintenance routines such new-age boilers provide.

Modulating Efficiency

Craig Lazinsky, marketing program manager, Bosch Thermotechnology Corp., said: “Contractors and service techs will undoubtedly see greater use of modulating gas condensing boilers in place of conventional cast iron boilers in 2015. Cast iron boilers have but one output: 100 percent capacity. Transitioning to a modulating, condensing, high-efficiency boiler allows the boiler to produce only the output required to satisfy demand. So, if there is a small load (one zone calling for heat, for example), the boiler will not operate at 100 percent output like a conventional cast iron boiler, but will instead operate as low as 20 percent — or a 5:1 turndown ratio — boosting energy efficiency, depending on model.”

Contractors are also selecting more cascading wall-mounted boilers for use in larger homes and light commercial spaces. Bosch Thermotechnology introduced a floor-standing option of the Greenstar gas condensing wall-hung residential boiler line in eight models with outputs up to 151 MBtuh. The Greenstar boilers are available in two versions: heat-only and combi boilers (heat and hot water). All eight floor-standing options come with the same components as their wall-mounted counterparts.

“Floor-standing models are ideal for applications when relocating the existing floor boiler and piping is impractical,” said Lazinsky.

Bosch also exhibited a line of stainless steel boilers with stainless steel heat exchangers for use in a range of spaces, from small residential apartments to large-scale commercial spaces. The eight SSB models can be vented using polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC), or polypropylene (PP) and have inputs ranging from 85 MBtuh to 1,024 MBtuh.

“We are fast approaching a time when mod/con boilers will be more popular than conventional cast iron models,” said Don DeCarr, hydronic product manager, ECR Intl. Inc. “Contractors will be looking for boilers with high AFUEs, simplified installation requirements, and advanced features that do not require specialized training.”

The company’s elite boilers qualify for Energy Star’s Most Efficient status with an efficiency rating of 95 percent AFUE.

Additionally, ECR’s SSC/VLT condensing technology products feature 95 percent efficiency, a self-cleaning patent pending heat exchanger, and reduce installation time and cost with built-in primary/secondary manifold and primary pumps, low-water cutoffs (LWCO), and plain-text controls.”

For Aerco Intl. Inc., the conversation centers on an increase in efficiency as manufacturers distance themselves from traditional noncondensing boilers.

“All of our equipment, for example, is high-efficiency and direct-fired,” said Bree McQuillan, vice president of marketing, Aerco.

Kunal Shah, product solutions manager, Aerco, said such products include the Benchmark models, which use stainless steel heat exchangers, air- or fuel-delivered systems, and a modulating burner. He noted the company’s line has now reached up to the Benchmark 6000, which produces 6 MMBtu.

Connectivity, Controls

Welch Goggins, president and CEO of Cleaver-Brooks, acknowledged a growing demand in integration and advanced controls, specifically in hydronics equipment.

“Cutting-edge technology has advanced controls that can save a facility as much as 50 percent in operating costs. This is done by focusing on the benefits of integration.”

The company showcased its ClearFire^®-C (CFC) vertical, down-fired boiler available from 500-3,300 MBtuh, and the ClearFire-LC (CFLC) available from 4,000-12,000 MBtuh.

The tubes in both the CFC and the CFLC feature patented ALUFER® technology, which provides an effective heating surface, the company said. The tubes are constructed from an inner (fireside) aluminum alloy finned surface, die-fitted within an outer duplex stainless or carbon steel tube that provides excellent heat exchange characteristics, stated Goggins.

The products are engineered with a modulating pre-mix burner and linkage-less control that automatically adjusts the air/gas mixture of the boilers to achieve up to 99 percent efficiency and 5:1 turndown, the company said. A symmetrical, 360-degree, even-temperature heat output from the burner is designed to ensure clean combustion with NOx emissions of less than 20 ppm as standard, the company said.

Mike Juhnke, product program manager, Lochinvar LLC, said he anticipates a greater emphasis on boiler controls and communication, granting boilers the ability to provide information electronically through text messages, Internet connectivity, and smartphone apps.

“In 2015, there will be more demand for boilers to interact with whole-home management systems and climate-control systems,” he said.

At the show, Lochinvar exhibited its Con-X-Us platform that provides two-way communication via Internet connectivity or through a smartphone app.

“Con-X-Us allows the user to make adjustments to the boiler remotely, from anywhere in the world, and provides the user with messages when something is not functioning properly,” said Juhnke.

Weil-McLain’s residential products manager, Mike Boyd, said another trend is “upgrading software for more equipment capabilities.”

In this regard, the company showed the Evergreen, a gas boiler that the company said “was designed for fast, easy installation in commercial and residential settings.” The Evergreen is suitable for retrofit applications in areas with limited space, boasts zone- and priority-based control, four circulator outputs, and MODBUS compatibility.

Publication date: 2/23/2015

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