The outside wall of a room is 4 × 3 m and 0.35 m thick. What is the energy loss per hour if the inside and outside temperatures are 35°C and −40°C respectively? Assume the conductivity of the wall is...

The outside wall of a room is 4 × 3 m and 0.35 m thick. What is the energy loss per hour if the inside and outside temperatures are 35°C and −40°C respectively? Assume the conductivity of the wall is 0.13 W/mK.

How much heat is transferred from a 25 ft × 24 ft surface by convection if the temperature difference between the front and back surfaces is 40°F and the surface has a heat transfer rate of 0.22 BTU/h ft2 °F?