Definitions


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Note:
The HTC includes both the convective and radiant transfer in a space.
Heat Transfer Coefficients (HTC)

Cooling: ex. 76 deg F room temp, 66 deg F surface

Floor = (76 deg F-66 deg F) x 1.2 Btu/hr/sf * deg F = 12 Btu/hr/sf
Wall =  (76 deg F-66 deg F) x 1.4 Btu/hr/sf * deg F = 14 Btu/hr/sf
Ceiling = (76 deg F-66 deg F) x 1.9 Btu/hr/sf * deg F = 19 Btu/hr/sf

Heating: ex. 70 deg F room temp, 84 deg F surface

Floor = (84 deg F-70 deg F) x 1.9 Btu/hr/sf * deg F = 28 Btu/hr/sf
Wall =  (84 deg F-70 deg F) x 1.4 Btu/hr/sf * deg F = 20 Btu/hr/sf
Ceiling = (84 deg F-70 deg F) x 1.1Btu/hr/sf * deg F = 15 Btu/hr/sf

In heating only, one can raise the wall and ceiling temperature to increase the output. For walls do not exceed a nominal 120 deg F and limit ceiling temperatures to a nominal 95 deg F

Learn more about indoor environmental quality.

Heat Loss to Head Loss, The Principles of Radiant Design