Brett Hedge, M.AIRAH
Integrated cooling/heating toward net-zero (direct) emissions
The presenters will consider two competing priorities in modern-day HVAC&R: the prolonged use of packaged comfort (cooling/heating) systems with little to no integration; and delivering energy-efficient and less carbon-intense refrigeration systems. This presentation will consider the use of R744 (CO2) as a base refrigerant for cooling and heating in the varying climate classifications within Australia.
Importantly, despite having a global warming potential (GWP) of 1, the use of R744 has not increased significantly in Australia. Although it has been state of the art in supermarkets for more than 10 years, it has failed to be captured as a mainstream technology outside of dedicated heat pump applications.
This study looks at conventional secondary cooling methods to combine and scale the best practices for heating and cooling in medium-large commercial retail and cold storage applications. This results in an integrated system that combines heating and cooling while providing the potential for net-zero direct emissions and optimal overall system efficiency.
Although technology and solution availability has evolved somewhat over the past 15 years, the extent of R744 usage is still heavily concentrated. The next evolution appears to be set for the same fate, with technology focused on one specific application and not for broader market appeal.
Additionally, alongside the desire for the most efficient and environmentally friendly refrigeration technology, there is a desperate need to consider the capabilities of technicians. In an industry that cannot keep pace with training requirements, it is important that scalable solutions are designed so that all levels of technician are able to maintain equipment. This is a difficult balancing act of trying to challenge convention and meet reliability expectations despite transient service technicians and companies with varying skill sets.
The research proves that there will be a need to further evolve and adapt solutions to achieve net zero. But there is a case for a system architecture that provides reliable operation, serviceability, and a significant reduction in overall system TEWI using R744 – not just in supermarkets but also in small-to-mid-size commercial cooling and heating applications.
The Sales and Marketing Manager for Kirby, Hedge has served in a number of engineering, technical sales and marketing roles since his time as a refrigeration and air conditioning apprentice/technician. More recently he has become a member of the Kirby leadership team, and his keen understanding of the trade has seen him become actively involved with AIRAH as a co-chair of the Special Technical Group for Refrigeration.
Hedge is a qualified refrigeration and air conditioning technician who holds an Advanced Diploma of Mechanical Engineering and a Bachelor of Business (Operations Management).
Herkess is the Segment Engineer for Kirby and has been with the company for more than 16 years in various sales and engineering roles. He is responsible for the “application” training of all staff and customers on CO2 systems and has led the delivery of this training to more than 300 technicians in the past 18 months.
With more than 25 years’ experience in the HVAC&R industry, Herkess has knowledge across most segments of refrigeration, from industrial to light commercial. He holds a national certificate in mechanical engineering and advanced trade certificates in refrigeration and air conditioning.