Piv nrog rau cov kav hlau, PPR cov kav dej muaj cov thermal conductivity tsawg, yog li lawv muaj qhov zoo me ntsis ntawm cov kav hlau hlau nyob rau hauv cov nqe lus ntawm kev txuag cua sov thiab Frost tsis kam. Tab sis nyob rau lub caij ntuj no, tsuav yog qhov kub thiab txias tsis txaus los tiv thaiv cov kav dej PPR los ntawm kev khov, muaj ob yam peb ua tau: Ua ntej, peb yuav tsum ntxiv cov khoom siv hluav taws xob rwb thaiv tsev thaum txhim kho cov kav dej, thiab ua kom zoo rwb thaiv tsev ntsuas. Thaum qhov kub tsis ncav cuag qis txaus, peb tuaj yeem xyuas kom cov kav dej tsis muaj khov; Thib ob, thaum qhov kub thiab txias tau qis heev, cov dej hauv cov yeeb nkab dej yuav tsum tau muab tshem tawm, lub ntsiab valve yuav tsum raug kaw, thiab cov dej hauv cov yeeb nkab dej yuav tsum tau muab tshem tawm kom tsis txhob muaj cov yeeb nkab dej khov.
