ClimateTalk Alliance is an organization of companies committed to developing a common communication infrastructure for HVAC and smart grid devices, enabling the interoperability of diverse systems. Created in 2009, the alliance’s members collaborate and drive the future of ClimateTalk, an open standards communication framework that enables simple connectivity among diverse HVAC and smart energy devices, leveraging existing industry standards for seamless information integration.

The design allows various components to send messages in a language understood by all equipment, no matter the brand.

ClimateTalk is a common information model developed for the exchange of information between disparate systems and devices. Designed to provide cost savings, control, and diagnostic capabilities for residential applications, ClimateTalk is standards-based and data-focused for simplified implementation. It also allows for independent decision-making within each device, providing flexibility, customization, and interoperability within a common framework. The basis of ClimateTalk was designed around standard communication protocol models, which allows for overall flexibility and expandability among numerous applications outside of HVAC. The open architecture also allows it to be adapted by any manufacturer.

It is the organization’s hopes that the ideology is embraced by the HVACR industry, making it the preferred communications model and, ultimately, the industry standard.

“By engaging key influencers from both the HVAC and smart grid communities, the ClimateTalk Alliance is bringing together important discussions on transforming the HVAC industry into the digital era to support the objectives of the utilities in managing peak load conditions,” said Diana Roberson, executive director. “By bringing together key players in HVAC, zoning, and water heating, the alliance is uniquely positioned to develop robust standards guided by the applied solutions technology experts.”


The Alliance has released three formal standards. Version 0.9 — the initial release included the HVAC Profile and CT-485 Protocol. Version 1.0 followed, addressing errata and the release of HAC Motor Profile and CT-LWP protocol. Version 1.3 expanded CIM (ClimateTalk Information Model), to include generic nodes and HVAC application derivatives such as packaged units, geothermal, and hydronic heating.

In addition to improving the basis of these standards, the working groups within the Alliance are preparing a new release greatly expanding the reach and capabilities of ClimateTalk, both in applications and connectivity.

On the application side, version 2.0 will include expansion of CT-485 to accommodate additional nodes and multiple nodes of the same type on the network. Additional modifications to the documentation have been done to lay the foundation for Wireless Interface Application specifications.

When the organization was created, it set goals to: build a vendor-neutral solution around a common information model for OEM differentiation; set direction for the future of the standard; and drive certification by an international standards board.

Roberson said the group has exceeded its goals in terms of progress in improving the robustness of the standards and capabilities of a ClimateTalk network. However, Roberson said she is disappointed with the slow rate of adoption within the HVAC industry, as well as support for an open standard.

“Our member base is highly motivated, but we are constantly challenged to broadly communicate the benefits of the standard and the Alliance with our small, nonprofit organization budget,” she said.

To further their mission, Climate-Talk Alliance formed an advisory group in January 2011. The advisory group serves as a proactive communication channel that enables members to stay informed while also providing a mechanism to provide observations, advice, and influence the development of the group’s standards.

That same month, the alliance released a White Paper, “Providing a Framework for Remote Access to Legacy Thermostats and a Pathway to Smart, Connected Systems.” The document outlines the concept that while the ClimateTalk information model fully supports communicating amongst indoor and outdoor units, the standards can also be used with legacy systems to provide remote access for even the most basic system. The paper examines the industry’s current closed protocol environment, where system-to-system communication is stunted, costs are high, and market confusion over how to protect intellectual property reigns supreme.

“In almost every industry, the move to a common standard has proven to drive lower costs, more robust solutions, consumer choice, accelerated innovation, and investment in technological advancements,” said Roberson. “With seven major OEMs influencing over 90 percent of all HVAC solutions, working together to provide a simple, consistent platform for communicating with the rest of the home, provides an opportunity to elevate the industry in the development of the connected home space.”

The Future

As the organization continues to grow, ClimateTalk Alliance members hope to see a major surge in the connected home space.

“The HVAC system is arguably the most complex automated system, as well as one of the most expensive when it comes to initial costs and power consumption,” said Roberson. “While the major HVAC OEMs are focused on protecting their ability to drive consumers to buy their matched indoor and outdoor units, the ClimateTalk Alliance has its eye on enabling the HVAC system, supported by an open HTML-based, data-centric, expandable network as the backbone of the connected home.”

In order to accomplish this, manufacturers should work together to create an easy-to-connect option rather than each brand operating on its own proprietary protocol. This would be a very important step for the industry.

“At Emerson, we’ve added communications to our equipment so that a wireless HVAC system has something to talk about and not just turn on or off,” said Joann Donelon, Emerson White-Rodgers. “As an industry we should strive to enable equipment with diagnostic and performance information that the homeowner can use in simple, energy-conscious decision making.”

The ClimateTalk Alliance is also focusing its future efforts on upgrading its certification. The ClimateTalk supported HVAC systems released initially were thoroughly tested for interoperability and compliance by the OEMs and suppliers. With the introduction of the zoning and water heater profiles, a scenario will arise when a new node will be added to an installed system.

“The standards are carefully designed to define minimum, mandatory requirements for each type of device to ensure end products behave as ‘good ClimateTalk citizens,’ ” said Roberson. “However, a formal test suite to support interoperability testing, as well as support member development efforts is underway. Anyone associated with compliance knows this is a huge, difficult task but the Alliance, with our volunteer army, we are going to make this happen.”

Sidebar: ClimateTalk Alliance Members

A.O. Smith Corp. and Emerson Climate Technologies serve as promoter members. Contributor members include ecobee Inc., EDC, EWC Controls Inc., Microchip Technologies Inc., Nidec Motor Corp., Nogginhaus LLC, Nordyne LLC, Research Products Corp., Varidigm Corp., and Zonefirst. Adopter members include Arzel Zoning Technology Inc., Broad-Ocean Motor, CABA, eControls Inc., Enertech Global LLC, Goodman Manufacturing Co., Honeywell, Jackson Systems LLC, Rheem Manufacturing Co., and Unico Inc.

Publication date: 9/17/2012