Experimental and numerical study of electronic module-cooling heat sinks used in a variable frequency air-conditioner outdoor unit

• Heat sink base area and fin height and pitch influence thermal performance.
• A proper tuning of heat sink configuration enhances thermal performance.
• Heat sink geometry and configuration is less influential for overall performance.

In variable-frequency Air Conditioner (AC), sizes of frequency controlling electronic module and its supplemental heat sink are much restrained and they are also tightly packed. Heat removal in such a limited space is difficult, and effective and compact heat sinks are required. The study has focused on heat sink thermal performance with different geometries and configurations. To allow for interaction of heat sink and fan, both numerical and experimental investigations are conducted in a real AC outdoor unit environment. An increase in heat sink base area significantly improves its thermal performance; fin height and pitch influence convective surface and also sweeping stream behavior and a good compromise is needed to enhance convective heat transfer. A proper tuning of heat sink configuration is effective to improve convective stream and subsequently enhance thermal performance. Heat sink geometry and configuration produces insignificant influence on fan aerodynamic and aeroacoustic performance, and AC system performance.