A　multi-unit　heat　pump　is　presented　for　simultaneous　humidity　and　temperature　control　to　improve　the　energy　efficiency　and　the　thermal　comfort.　Two　parallel　connected　condensers　are　employed　in　the　system,　locating　at　the　back　of　the　indoor　evaporator　and　the　outdoor　unit,　respectively.　The　heat　pump　can　operate　in　four　modes,　including　heating,　cooling　and　dehumidification　without　and/or　with　partial　or　total　condensing　heat　recovery.　The　experimental　investigation　shows　that　the　temperature　control　capacity　is　from　3.5　kW　for　cooling　to　3.8　kW　for　heating　with　the　cooling　and　heating　efficiency　higher　than　3.5　kW　kW(-1),　and　the　dehumidification　rate　is　about　2.0　kg　h(-1)　with　the　efficiency　about　2.0　kg　h(-1).kW(-1).　The　supply　air　temperature　and　humidity　can　be　simultaneously　regulated　with　high　accuracy　and　high　efficiency　by　adjusting　the　indoor　and/or　outdoor　air　volumes.　It　provides　an　integrated　and　effective　solution　for　simultaneous　indoor　air　temperature　and　humidity　control　for　all-year-round　operation　in　residential　buildings.　(C)　2013　Elsevier　Ltd.　All　rights　reserved.