This　paper　aims　at　enhancing　the　boiling-condensation　co-existing　phase　change　heat　transfer　process　inside　a　small　and　closed　space　by　inserting　copper　foams　into　the　space.　The　working　fluid　is　deionized　water.　The　pore　density　of　copper　foam　used　is　20　PPI　and　the　porosity　is　0.96.　The　inserts　used　include　cut　and　non-cut　copper　foam　blocks.　Experiments　were　carried　out　to　study　the　influences　of　working　fluid　filling　ratio,　cut　and　non-cut　copper　foam　blocks　on　boiling　and　condensation　co-existing　heat　transfer　inside　a　small　and　closed　space　that　is　60　mm　in　diameter　and　33　mm　in　height.　Experimental　results　show　that,　although　there　is　an　optimum　filling　ratio　for　boiling　heat　transfer　coefficient　obtaining　its　largest　value,　there　is　no　such　optimum　ratio　for　condensation　if　the　space　is　filled　with　non-cut　copper　foam　block.　However,　if　the　space　is　filled　with　the　cut　copper　foam　block,　then　there　is　an　optimum　filling　ratio　at　which　both　boiling　and　condensation　heat　transfer　coefficient　acquire　their　maximum　value.　Compared　with　that　without　copper　foam　inserts,　although　inserting　non-cut　copper　foam　block　into　the　space　can　enhance　boiling　heat　transfer,　it　weakens　condensation　and　the　overall　heat　transfer　process;　and　inserting　the　cut　copper　foam　block　can　enhance　both　boiling　and　condensation　heat　transfer　and　therefore　is　a　good　practice　for　enhancing　the　boiling-condensation　co-existing　phase　change　heat　transfer　process　inside　small　and　closed　spaces.　(C)　2016　Elsevier　Ltd.　All　rights　reserved.