Recommended by the IIR / IIR document

Air-air split AC with minimum charge of propane.

Number: 0010



This paper describes technology for an environmentally friendly split type air conditioner, characterized by using safe amounts of propane as refrigerant. The objective was to demonstrate a system, using less than 150 g of propane, providing minimum 3.5 kW cooling capacity with a COP2≥3.5 at air flows that allow acceptable noise levels.
The condenser and evaporator were of standard microchannel type. The evaporator headers were rebuilt to reduce charge and different techniques were tested for even refrigerant distribution. A DC-motor scroll compressor for AC in electric vehicles was used, characterized by small internal volumes, small oil charge and wide capacity range (800-8500 rpm). The system also included a specially built minichannel liquid/suction line heat exchanger and a standard electronic expansion valve. The connection lines in-between the indoor and outdoor unit were 6 m long.
The project target was reached with a charge of 143 g propane.

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Pages: 12 p.


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  • Original title: Air-air split AC with minimum charge of propane.
  • Record ID : 30029655
  • Languages: English
  • Subject: Technology
  • Source: 15th IIR-Gustav Lorentzen Conference on Natural Refrigerants(GL2022). Proceedings. Trondheim, Norway, June 13-15th 2022.
  • Publication date: 2022/06/13
  • DOI:
  • Document available for consultation in the library of the IIR headquarters only.


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