According　to　the　temperature　regulations　and　high　energy　consumption　of　air　conditioning　(AC)　system　in　data　centers　(DCs),　natural　cold　energy　becomes　the　focus　of　energy　saving　in　data　center　in　winter　and　transition　season.　A　new　type　of　air-water　heat　exchanger　(AWHE)　for　the　indoor　side　of　DCs　was　designed　to　use　natural　cold　energy　in　order　to　reduce　the　power　consumption　of　AC.　The　AWHE　applied　micro-heat　pipe　arrays　(MHPAs)　with　serrated　fins　on　its　surface　to　enhance　heat　transfer.　The　performance　of　MHPA-AWHE　for　different　inlet　water　temperatures,　water　and　air　flow　rates　was　investigated,　respectively.　The　results　showed　that　the　maximum　efficiency　of　the　heat　exchanger　was　81.4%　by　using　the　effectiveness　number　of　transfer　units　(epsilon-NTU)　method.　When　the　max　air　flow　rate　was　3000　m(3)/h　and　the　water　inlet　temperature　was　5　degrees　C,　the　maximum　heat　transfer　rate　was　9.29　kW.　The　maximum　pressure　drop　of　the　air　side　and　water　side　were　339.8　Pa　and　8.86　kPa,　respectively.　The　comprehensive　evaluation　index　j/f(1/2)　of　the　MHPA-AWHE　increased　by　10.8%　compared　to　the　plate-fin　heat　exchanger　with　louvered　fins.　The　energy　saving　characteristics　of　an　example　DCs　in　Beijing　was　analyzed,　and　when　the　air　flow　rate　was　2500　m(3)/h　and　the　number　of　MHPA-AWHE　modules　was　five,　the　minimum　payback　period　of　the　MHPA-AWHE　system　was　2.3　years,　which　was　the　shortest　and　the　most　economical　recorded.　The　maximum　comprehensive　energy　efficiency　ratio　(EER)　of　the　system　after　the　transformation　was　21.8,　the　electric　power　reduced　by　28.3%　compared　to　the　system　before　the　transformation,　and　the　control　strategy　was　carried　out.　The　comprehensive　performance　provides　a　reference　for　MHPA-AWHE　application　in　data　centers.