Kev sib tshooj kis rau kev sib tshooj yog qhov chaw siv rau lub khw kev sib tshooj thiab lwm yam khoom siv rau kev tsim ib qhov chaw sib tshooj hauv ib qho khoom siv uas muaj kev sib tshooj zoo, tshwj xeeb tshaj plaws rau cov khoom siv hluav taws xob xws li cov pa rooj, cov kuab, thiab cov khoom siv hauv qab zib. Lub tswv yim ntawm nws yog kom txo qhov kev sib tshooj, uas yog qhov thaum kub dhau los ntawm qhov chaw sib tshooj, ua rau kub tsis meej, thiab tshav kub tsis zoo. Lub khw no tsis yog ib qhov chaw ntxig ntxig, tab sis yog ib qhov chaw muaj kev sib tshooj tsis zoo uas tau xaiv tshwj xeeb thiab muaj kev txiav txim siab kom txiav txim siab tshaj qhov chaw hluav taws xob hauv qab thiab saum toj. Cov khoom siv tshwj xeeb tshaj plaws rau qhov no yog cov khoom siv polymer muaj zog, tshwj xeeb tshaj plaws polyamide siv hluav taws kab (xws li PA66 GF25/30), uas muaj kev sib tshooj kub tsis zoo (~0.3 W/m·K) thiab muaj zog tshaj plaws rau kev tso tawm thiab kev tso tawm los ntawm hluav taws xob thiab kev tso tawm hauv qab zib. Qhov kev ua haujlwm ntawm lub khw sib tshooj kub yog qhov thermal transmittance (Ψ-value, Psi-value), uas muaj feem cuam rau qhov kub loss hauv qhov chaw sib sau. Lub khw sib tshooj kub yooj yim tshaj plaws yuav tsum muaj kev nyob ntev, uas xav tau kev nyob ntev rau kev tso tawm, kev tso tawm kub, kev tso tawm UV (yog tias tso tawm), thiab kev tso tawm dej. Kev tsim kho, tshwj xeeb tshaj plaws yog kev tsim kho nrog kev tsim kho nrog kev tsim kho nrog aluminum windows, yog qhov tseem ceeb rau kev tshuaj xyuas kom muaj kev sib sau zoo thiab kev sib sau zoo ntawm lub khw thiab hluav taws xob. Lub khw no yog ib qhov tseem ceeb rau kev tsim kho tseem ceeb, uas tuaj yeem pab kom txo qhov kub, pab neeg nyob zoo dua los ntawm kev nce qhov tshav kub hauv qab, tshem tawm qhov kub, thiab txhob tshem tawm qhov kub, thiab txhob tshem tawm qhov kub, thiab txhob tshem tawm qhov kub.