In　recent　years,　microchannel　heat　exchangers　have　begun　to　be　used　in　refrigeration　and　air　conditioning　systems.　This　paper　introduces　a　microchannel　condenser　for　domestic　refrigerators　with　a　theoretical　model　to　evaluate　its　performance.　The　model　was　used　to　obtain　the　optimal　design　parameters　for　different　numbers　of　tubes　and　tube　lengths.　The　results　show　that　the　needed　tube　height　of　the　downward　section　decreases　with　the　number　of　tubes　and　the　tube　diameter.　Compared　with　the　original　condenser,　the　present　optimal　design　parameters　can　reduce　the　total　metal　mass　by　48.6　for　the　two　wall　two　side　design　and　by　26　for　the　two　wall　one　side　design.　Thus,　the　present　condenser　is　much　better　than　the　condensers　usually　used　in　actual　domestic　refrigerators.　©　2010　Tsinghua　University　Press.