To　fully　utilize　natural　cold　sources,　a　novel　integrated　unit　is　proposed　and　tested,　which　uses　a　mechanically-driven　loop　heat　pipe　(MLHP)　system　to　assist　the　vapor　compression　refrigeration　(VC)　system　for　data　centers　(DCs)　cooling.　This　integrated　unit　can　operate　four　modes,　namely,　VC　mode,　booster-driven　loop　heat　pipe　with　throttle　valve　(BLHP-T)　mode,　booster-driven　loop　heat　pipe　(BLHP)　mode　and　liquid　pump-driven　loop　heat　pipe　(PLHP)　mode.　The　optimal　switching　temperatures　of　the　integrated　unit　in　different　modes　are　obtained.　When　the　outdoor　temperature　(OT)　is　above　23℃,　the　VC　mode　should　be　used,　and　the　BLHP-T　mode　should　be　used　when　the　OT　is　at　10℃–23　℃.　In　addition,　when　the　OT　is　at　−4℃-10℃,　the　composite-driven　loop　heat　pipe　(CLHP)　mode　can　be　operated,　and　when　the　OT　is　below　−4℃,　the　PLHP　mode　performs　better.　In　addition,　the　optimal　control　strategy　is　designed　and　the　energy-saving　potential　is　evaluated.　The　integrated　unit　applied　in　cold　regions　has　higher　energy-saving　potential　than　in　warm　or　other　regions,　and　the　energy-saving　rate　is　24.73%　in　Harbin,　0.96%　in　Hainan,　which　indicates　that　the　integrated　unit　is　more　suitable　for　northern　regions　rather　than　southern　regions.　©　2024　Elsevier　Ltd