A radiant-heating system is installed in the plaster ceiling of a room 36 ft long by 18 ft wide by 9 ft high. Assume direct radiation. The temperature of the concrete floor is maintained at 75°F. The temperature of the air passing through the room is held at 75°F. If the required heat supply to the floor is 8000 BTU/hr, calculate the necessary temperature at the ceiling surface. How much heat is transferred to the air, in BUT/hr? Emissivity of plaster = 0.93; absorptivity of concrete = 0.63. The convective heat-transfer coefficient between the ceiling and the air is given by the equation hc = 0.20 (AT)1/4.

A radiant-heating system is installed in the plaster ceiling of a room 36 ft long by 18 ft wide by 9 ft high. Assume direct radiation. The temperature of the concrete floor is maintained at 75°F. The temperature of the air passing through the room is held at 75°F. If the required heat supply to the floor is 8000 BTU/hr, calculate the necessary temperature at the ceiling surface. How much heat is transferred to the air, in BUT/hr? Emissivity of plaster = 0.93; absorptivity of concrete = 0.63. The convective heat-transfer coefficient between the ceiling and the air is given by the equation hc = 0.20 (AT)1/4.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter1: Basic Modes Of Heat Transfer

Section: Chapter Questions

Problem 1.67P: 1.67 In beauty salons and in homes, a ubiquitous device is the hairdryer. The front end of a typical...

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