By　analyzing　the　energy　transfer　process　of　building　ventilators　with　heat　recovery,　a　novel　building　ventilator　with　exhaust　air　heat　pump　enhanced　by　pump-driven　loop　heat　pipe　system　was　proposed　and　experimentally　compared　with　the　dual-loop　heat　pump　and　traditional　heat　pump　system.　During　the　test,　the　thermal　per-formance　of　the　prototype　under　three　different　operating　modes　was　comprehensively　studied,　and　then　the　energy-saving　potential　and　applicability　of　the　heat　recovery　units　in　the　ultra-low　energy　buildings　(ULEBs)　were　analyzed　by　using　the　DEST　and　MATLAB　tools.　Results　showed　that　compared　with　the　heat　pump　system,　the　composite　system　presented　the　highest　energy　efficiency　ratio　(EER)　in　the　whole　year,　at　12.6　for　winter　and　4.8　for　summer　conditions,　respectively.　What＇s　more,　the　energy　recovered　by　the　composite　system　is　in　line　with　the　fresh　air　load,　which　can　solve　the　problem　of　energy　recovery　attenuation　of　traditional　ventilators　in　cold　climate　conditions.　In　addition,　the　composite　system　had　great　applicability　in　ULEBs,　and　the　energy　-saving　ratio　was　35.3%　and　14.5%　in　Harbin　and　Kunming,　respectively.　Future　works　are　to　improve　the　performance　of　the　pump-driven　loop　heat　pipe　and　heat　pump　unit　under　all　operating　conditions　for　better　adaptability　of　the　ventilators.