Erre gondoltam:

"For most applications, heater facing should not be thicker than 5”. Thicker facing will decrease rate of heat transfer under typical firing schedule. Surface temperatures will also decrease, and it may result in a heat transfer rate that cannot match speed of heat loss of the given area unless firing pattern is changed"

Meg erre: "Our experience shows that heaters with facing of 4” to 5”thick offer ideal solution for most applications in our continental climate here, in Canada."

Később ő is írja, hogy jobban hőszigetelt házba a vastagabb falú jobban érvényesül, mert ott egységnyi idő alatt kisebb hőleadás kell, és a nagyobb tömeg miatt tovább tarja a meleget.