Dab tsi yog 1.5 teev hluav taws qhov rooj?

Qhov rooj rated rau 1-1 / 2 teev yuav tsum muaj nyob rau hauv 2- teev rated phab ntsa. Cov qhov rooj no feem ntau nyob hauv stairwells, lossis lwm cov kab txuas ntawm cov kab ntsug ntawm lub tsev. Lawv kuj tshwm sim hauv chav Boiler thiab cov phab ntsa sab nrauv uas muaj peev xwm rau kev raug hluav taws kub sab nraud.