Sandaro watau condensation shine canjin yanayin al'amari na dan lokaci daga matsayin iskar gas zuwa ruwa, da kuma shi ne maimakon tururi wato vaporization. Kalmar galibi tana nufin zagayowar ruwa. Hakanan ana iya bayyana shi azaman canji a cikin yanayin tururin ruwa zuwa ruwa mai ruwa lokacin da ake hulɗa da ruwa ko tsayayyen farfajiya ko kuma iskar ƙanƙara ta cikin iska. Lokacin da canjin ya faru daga lokacin gas zuwa cikin madaidaicin lokaci kai tsaye, ana kiran canjin ajiya. Sandaro na fara shi ne ta hanyar samar da tarin atomic/kwayoyin halittar wannan nau'in a cikin ƙarar gas ɗinsa - kamar ruwan sama ko samuwar dusar ƙanƙara a cikin gajimare - ko a saduwa tsakanin irin wannan lokaci na gas da ruwa ko ruwa mai ƙarfi. A cikin gajimare , ana iya sarrafa wannan ta hanyar sunadarai masu narkar da ruwa, waɗanda microbes na yanayi ke samarwa, waɗanda ke da ikon ɗaure ƙwayoyin gas ko na ruwa.