The vapor from the moduledid notaffectmain7plastic unitsofthe airconditioner, whereas theViscopearl equipped withanair conditioner showed good mosquito repellency under test chamber and room conditions that temperature, relative humidity, and carbon dioxide concentration were controlled at 24.8–25.4°C, 63.8–65.7%, and 708–1383ppm,respectively.Therefore,theplantessentialoil-basedrepellentViscopearlhashighpotentialtobe used as human protective agent against indoor mosquitoes by applying it to air conditioners.