If Bob Dylan was right about one thing, it’s that “the times, they are a’changin”, and that’s never been more true than in the refrigerant and HVACR industries right now. In this two-part series, we dive into the present and future of chiller tech — what’s happening in the HVACR world right now and how technicians can expect the industry to change as time goes by.
The European F-Gas regulation and the phasedown of high-GWP refrigerants — and resulting impact on refrigerant price — have driven recognition in all regions that high-GWP refrigerant use comes with long-term environmental and cost risks. That’s according to Drew Turner, global marketing manager – Oil-free Solutions, Danfoss. In the U.S., in the absence of federal direction, states and cities (including California and the growing U.S. Climate Alliance) are taking steps to reduce high-GWP refrigerants, driving change throughout the industry.
“Regulations that focus on environmental sustainability and energy efficiency are creating opportunities to improve overall HVAC products and system designs as the industry continues to evaluate long-term viable solutions,” said Brian Smith, director of global marketing – Chiller Solutions, Johnson Controls Inc. “The HVAC market is continually driving toward system efficiency, sustainable solutions, connectivity, and cloud-based services.”
Chiller technologies align with these market trends.
“Flammable refrigerants will require changes to not just equipment, but also to building design, handling, maintenance, and operating procedure,” Smith continued. “New, holistic approaches are needed that consider the life cycle of the equipment within its environment, regarding costs, greenhouse gas emissions, and interfacing with constantly evolving data management systems.”
By 2050, it is expected that 70 percent of the world’s population will live in cities, compared to 54 percent today, said Turner. In fact, about 77 million people are moving from rural to urban areas around the world each year.
“This is causing an accelerating trend toward equipment optimized for retrofit applications, with minimized footprint and sound levels,” Turner said. “The centralized fossil fuel-driven electric grid is shifting to one that is decentralized, with microgrids and the integration of renewables. With that is coming a shift to ‘electrification,’ changing equipment that formerly used fossil fuels, primarily for heating, to become electric-driven. The trend toward energy storage is being influenced by the periodic availability of renewables and the resulting disconnect with demand.”
A related buzz term is the water-energy nexus, which refers to the issues surrounding cities’ needs for water and the energy consumed to treat and transport it.
“This has driven recognition that these costs should be accounted for in making equipment decisions,” Turner said.
Chiller component efficiencies are approaching practical and, in some cases, thermodynamic limitations, said Smith. At the same time, the ways in which HVAC systems are operated offer opportunities for energy savings that are proving to be much greater than smaller incremental savings in certain component technologies. For example, the York® YHAU Chiller/Heat Pump is designed with absorption technology that utilizes zero-GWP water as a refrigerant, and uses available waste heat rather than disposing of it. It provides a dual benefit for end users on overall energy consumption and lower operating costs.
“System efficiency, while challenging, is becoming prevalent in building and equipment design through Green Globes, the USGBC [U.S. Green Building Council] LEED green building certification program, and other programs with the intent to help building owners measure and reduce energy consumption,” he said.
That includes advanced control schemes, model predictive control, system optimization, artificial intelligence, equipment learning (to optimize the real-time complexities of operating systems), and wireless connectivity for remote aggregation and analysis of system data (to inform operational decisions and identify and prioritize maintenance schedules to avoid unplanned or extended downtime for repairs).
“Whether it is global, national, or local-level regulatory decisions, sustainability and the efforts to reduce lifetime greenhouse gas emissions will continue to be a focal point, focused on improving efficiency and driving refrigerant choice,” Smith said.
Refrigerants are no longer a set-and-forget factor with equipment installation, said Turner.
“The market has recognized that chillers spend a significant amount of time operating at off-design or part-load conditions,” he said.
Expectations continue to grow around technology and equipment turndown capability, either through variable-speed operation or additional compressor technology unloading steps.
“This is partly driven by a growing understanding that the average chiller is oversized to even the design load,” Smith continued. “Not only are the average chillers spending more than 99 percent of their time operating at capacities below the design point, but the chiller is oversized to that design point.”
This has led to revisions and increases/improvements of chiller part-load performance metrics in the U.S. and other regions. It also spurred a growing trend toward testing on real-life operating conditions, including after manufacturing as well as during ongoing commissioning through monitoring and instrumentation and/or recommissioning.
“While air-cooled chillers were typically seen as a standard or ‘packaged’ product, customers now expect much more from them,” said Chris Opie, vice president, product marketing and platform strategy, Carrier Commercial HVAC Global Equipment. “To gain meaningful efficiency increases, the entire system should be evaluated. Instead of providing just chilled water at nominal conditions, they now need to have much broader operating ranges to increase the performance of the entire system. Heat recovery, free cooling, surge-resistant compression, and low-lift performance can enable better overall system efficiency. Based on their building’s specific needs, air-cooled chillers are approaching the level of customized, application-specific products. This means different levels of energy efficiency, wider operating range, and extra quiet, all while fitting into the footprint of the machine they are replacing.”