Dr Lamb's presentation revisits the ongoing debate around refrigerant selection as the sector responds to regulatory pressure, rising energy costs and the shift away from high-GWP gases. Building on analysis first shared at Cold Chain Live 2025, Dr Lamb will present updated modelling and operational data comparing ammonia and CO2 systems in cold storage and freezing applications, with emphasis on lifecycle cost, energy efficiency and long-term resilience.

Both refrigerants remain central to industrial decarbonisation strategies. Ammonia continues to demonstrate high efficiency and long service life in large-scale installations, while CO2 offers compact, non-flammable solutions that can be cost-effective at smaller capacities and low-temperature duties. However, sustained increases in electricity prices for non-domestic users, up more than 270% since 2015, have sharpened the focus on energy performance.

Using a 35,000m³ cold store model operating at –22°C with a 35°C design ambient, Dr Lamb’s analysis shows annual energy consumption of around 910,000kWh for a low-charge ammonia system compared with approximately 1.25 million kWh for a transcritical CO2 plant under the same conditions. At an electricity price of 25p per kWh, this represents an annual operating cost difference of roughly £86,000. According to the modelling, such divergence can materially influence the total cost of ownership, with lifecycle performance offsetting any initial capital cost advantage of CO2 in certain scenarios.

Dr Lamb said the discussion should not be framed as a competition between the two refrigerants, noting that both have a clear role depending on application requirements. He added that decision makers must weigh capital cost, operating efficiency, compliance and long-term resilience when selecting plant.

The session will also examine how packaged low-charge ammonia systems are addressing historic concerns around complexity and safety by reducing refrigerant charge and simplifying installation.

The Industrial Refrigeration Network Conference, hosted by Bitzer at its Schaufler Academy, brings together manufacturers, contractors, and end users from across the sector. Star Refrigeration’s involvement reflects its commitment to evidence-based engineering and informed technical debate.

Further information and registration details are available at: https://trainings-events.bitzer.de/microsite/index.cfm?l=2797&modus=