ʻO ka panela sanwika hoʻonaninani i kālai ʻia metala hale Dongan, he ʻano mea hou ia no ka insulation hale waho a me ka hoʻonaninani, kahi mea i makemake nui ʻia e nā mea kūkulu hale. Loaʻa i loko nā ʻano mea like ʻole me ka nui o ka mānoanoa, e like me pu, eps, pir a pēlā aku. ʻO ka ʻili he pepa kila i uhi ʻia me ka alloy AL-ZN. A no ka insulation, pale ahi a me ka pale pulu, hoʻohana ka mea lalo i ka papa alumini foil, nona ka hana maikaʻi loa ma ka insulation a me ka pale pulu.
