Roolaha sare waa qayb muhiim ah oo ka mid ah unugga fuser-ka. Fiyuuska sare ayaa inta badan gudaha ka banaan waxaana lagu kululeeyaa nalalka kuleyliyaha ah. Tuubooyinka rogrogmada sare ee tayada sare leh waxay inta badan ka samaysan yihiin walxo aluminium saafi ah oo leh darbiyo dhuuban si loo hubiyo kuleyl wax ku ool ah. Waxaa caadi ahaan loo yaqaan "Roller thethermal".