VEHICULAR AIR CONDITIONER

To provide a vehicular air conditioner enabling suppression of deterioration of fuel economy of a vehicle and comfort in a cabin.SOLUTION: A vehicular air conditioner 1 includes: an inside air concentration estimation section 78 estimating an inside air concentration ρi that is a concentration of harmful substances in inside air; an outside air concentration estimation section 79 estimating an outside air concentration ρo that is a concentration of harmful substances in outside air; an inside/outside air mode determination section determining an inside/outside air mode of opening/closing states of an inside air introduction port 511 and an outside air introduction port 512 to be an inside air mode or an outside air mode on the basis of the inside air concentration ρi and the outside air concentration ρo; and a compressor control section controlling an operating state or a stopped state of the compressor on the basis of a change of the inside/outside air mode.SELECTED DRAWING: Figure 2 【課題】車両の燃費および車室内の快適性の低下を抑制する車両用空調装置を提供する。【解決手段】車両用空調装置１は、内気における有害物質の濃度である内気濃度ρｉを推定する内気濃度推定部７８と、外気における有害物質の濃度である外気濃度ρｏを推定する外気濃度推定部７９と、内気濃度ρｉおよび外気濃度ρｏに基づいて、内気導入口５１１および外気導入口５１２の開閉状態である内外気モードを内気モードか外気モードに決定する内外気モード決定部と、内外気モードの変化に基づいて、圧縮機の稼働か停止かの状態を制御する圧縮機制御部と、を備える車両用空調装置。【選択図】図２