International Institute of Refrigeration
Ammonia and CO2 Refrigeration Technologies
International Conference
- Ohrid 2021 -

Keynote Speakers

Dr Andy Pearson Dr Andy Pearson, UK,
Star Refrigeration Ltd
President of Scientific Committee
Former President of IoR UK,
Member of IIR Commission E1
"Optimising energy use in refrigeration systems" 
Dr Predrag Hrnjak Dr Predrag Hrnjak, USA,
University of Illinois
Member of IIR Commission E2,
Former member of IIAR Board of Directors
"Efficient and compact a/c system for high-speed trains based on CO2."
Dr Andy Pearson Stefan Jensen, Australia,
Scantec Refrigeration
Managing Director
“The future of low charge NH3 refrigerating plants." 
Dr Predrag Hrnjak Dr Zahid Ayub, USA,
Isotherm, Inc.
Fellow of ASHRAE and ASME,
"Role of Enhanced Surface Heat Transfer in
Ammonia and CO2 Refrigeration Systems ..."
Dr Andy Pearson Sergio Girotto, Italy,
Enex Srl
"CO2 as a refrigerant: what can we expect in future?”

Main Topics of the Conference  
Design of modern ammonia (NH3) systems and technological innovation
Lowering of ammonia charge in the systems; Medium and small size ammonia systems;  
Advanced design; Factory-made units;
Compatibility of ammonia with metals and new oils.

Design of carbon dioxide (CO2) refrigeration and heat pump systems
Transcritical and subcritical operation;
Modifications of cycles to improve the energy efficiency;
Development of CO2 systems intended for hot climate;
Ejector as an expansion device.

New innovative components
Plate and “shell & plate” heat exchangers; DX evaporators;
Microchannel air-cooled condensers; Improved evaporative condensers;
Semi-hermetic and hermetic ammonia compressors;
High-pressure ammonia and CO2 compressors.

Energy efficiency of ammonia and CO2 refrigerating systems
Advantages of ammonia and CO2 versus fluorocarbon-based systems;
New secondary coolants; CO2 as a secondary coolant;
NH3/CO2 cascade systems.

Applications of ammonia and CO2 refrigeration
Cold stores, food and drink industries; Supermarkets; Air-conditioning systems (liquid chillers);
Heat pumps (medium and high temperature heating).

Absorption machines
Modified absorption cycles; Trigeneration and district cooling.

Ammonia and CO2 systems in developing countries
Modernisation, improvements, technical assistance, barriers.

Technical and safety issues; Guidelines and training materials
Regulations on the construction and operation of ammonia and CO2 refrigerating systems;
Education and training for: best practices, operating procedures, handling and safe operation.

Public awareness of the image and benefits of natural refrigerants
Crucial and sustainable contributions to a better environment; Barriers to market penetration;
Current and future use of natural refrigerants; Montreal Protocol and Kigali amendment, phase-down of HFCs.