Industrial / Warehouse

Courschene Larose (Michal inc.)


The major task of food processing applications today is to ensure the freshness of perishable goods. Storages are used to smooth out highs and lows in production, allowing a more continuous supply to customers, and help maintain the quality of produce.


The warehouse of Courchesne Larose (Michal Inc.) is spread over an area of 100,000 ft2 with 40 ft. of height, able to accommodate 2 069 945 kg (4 563 442 lbs) of food per day. It includes 22 ripening rooms for bananas, a main dock with 19 garage doors, a banana dock with 3 garage doors. The temperature in the rooms varies between 0 and 15˚C.

Carnot Refrigeration Inc. has designed and manufactured a tailored system for this warehouse. Our refrigeration system with NH3/CO2 provides effective and reliable cooling, with an increase of the energy afficiency (4 times better than in the former warehouse). In addition, the use of CO2 and reducing the level of ammonia used increase the safety of the building for its workers and neighbors, while minimizing the negative impact of traditional refrigerants on the environment. 

It should be noted that Carnot Refrigeration has incorporated new technologies such as the total recovery of the heat generated by the compressors and free cooling.

Although the technology is innovative, it is now proven, optimized and reliable.



 The major advantages of this technology

Security and Environment

  • Totally eliminating the use of HFC’s and / or HCFC’s
  • Drastically reducing the quantity of ammonia without energy penalty. 
  • Ammonia contained in the mechanical room

Installation savings

  • Reducing the use of paraseismic hangers and the structural need to support the pipes
  • Reducing piping and insulation size by more than half and the related labour and material cost by 31.5 %

Energy savings

  • Providing full heat recovery (if needed) for space heating or water heating (domestic or processed)
  • Free cooling mode allows to shut down the ammonia compressors, meaning substancial energy savings and equipment preservation
  • Drastic increase in energy efficiency. The owners were able to quadruple the storage area while maintaining the same energy as in their old warehouse, 4 times smaller. It means that our system is 4 times more efficient than their former one

About the System

Hot Gas Defrost

Hot gas provides a quick and efficient evaporator defrost. Compared with electric defrost, this method has the advantage of zero additional energy expenditure or adding heat in the energy balance of the system. Hot gas defrost offers the possibility of heating the docks and all other areas of the warehouse as needed, always without additional energy expenditure and no additional mechanical equipment (pumps, loop glycol, heaters, etc.).

Heat recovery

The NH3/CO2 refrigeration system is designed to recover direct heat from the discharge gases of the CO2 compressors to fuel recovery coils, to heat the ambient air of offices and the warehouse space that requires heat, such as the shipping dock and workshop. This option provides recovery capacity (available heat) up to 8 times greater than with the use of an intermediate loop glycol.

FC – Mode « Free Cooling »

Using CO2 by direct expansion in cascade with ammonia, our system stays in FC mode (free cooling) when the outside temperature is below 8 °C. This mode is maintained for 4,000 hours in the Montreal area.

During these hours of FC mode, NH3 compressors remain completely stopped. These breaks increase the lifetime of the compressors, the lubrication system and other components of the ammonia loop.

In comparison, a recirculation loop with CO2 kept at -8°C outside temperature will remain below -15 °C to allow the TFC mode. It corresponds to a potential of 250 cars in the Montreal area. We expect that this system will reduce the total energy (kWh) requirement of the building compared to a direct NH3 system.