Mitsubishi Heavy Industries Technical Review
    Vol. 60 No. 2 (2023)   Logistics, Thermal & Drive Systems
    Technical Papers

    Overview of the Development of the SRK_23S Series of Residential Air Conditioners with Improved Heating Capacity to Achieve Carbon Neutrality

    MASASHI TAKANO
    YOSHINORI NUNOME
    NAOMICHI UNO
    MASAKAZU KUHARA
    TAKURO FUJIWARA
    MICHIAKI NAKANISHI

    Attention has been focused on heating with a heat pump (HP) as a major technology to achieve carbon neutrality (CN), because such HPs emit a smaller amount of greenhouse gases than fossil fuel combustion heaters. However, further improvement in the efficiency of HP heating is also required to reduce CO2 emissions from power consumption, in addition to shoring up a weak point due to its characteristics, that is, the capacity when the outdoor air temperature is low. The recent housing situation is increasing the number of cases in which residential air conditioner is installed to cool/heat a living-and-dining-combined space of 20 tatami mats (approximately 36.48m2) or more, resulting in a rise in the need for large-capacity air conditioners. Under such circumstances, Mitsubishi Heavy Industries Thermal Systems, Ltd. added newly developed room air conditioners for 2023 to its product lineup. These include the air conditioners with cooling capacity of 6.3, 7.1 and 8.0kW for living rooms with the realization of a 13% energy saving performance improvement compared with the existing models, and the new models for cold climates with a substantial capacity improvement at low outdoor air temperatures.