Hongu, jira rakarukwa rinogona kuvhara mhepo, uye rinotoshanda kupfuura rakarukwa. Kuti jira rakarukwa rinopera here zvinoenderana nekuti harina ruvara here.
Nezvekuita kwejira rakarukwa risingapindi mhepo: Nekuda kwekuwanda kwaro uye akawanda mapoinzi anopindirana, jira rakarukwa rine chimiro chakasimba uye harina porous sejira rakarukwa. Ichi chimiro chechimiro chinopa jira rakarukwa kuchengetedza kudziya kuri nani munguva yechando, zvichireva kuti haipindi mhepo. Naizvozvo, jira rakarukwa rinonyanya kushanda pakuvhara mhepo kupfuura jira rakarukwa.
