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Influence of Infrared Radiation on Attic Heat Transfer
Abstract
An experimental study concerned with different modes
of heal transfer in fibrous and cellulose insulating material
is presented. A series of experiments were conducted using
an attic simulator to determine the effects of ventilation
on attic heat transfer, and the effect of infrared radiation
on the thermal conductivity of the insulation system and
on attic heat transfer. All the tests were performed at
steady state conditions by controlling the roof deck temperature.
Calculations are performed for insulation thicknesses
between 1 inch (2.54cm) and 6.0 inches (15.24cm)
and roof deck temperatures between 145°F (62.78°C) and
100°F (36.78°C).
The temperature profiles within the insulation were
measured by placing thermocouples at various levels within
the insulation. The profiles for the cellulose insulation are
linear. The profiles within the glass fiber insulation are
non-linear due to the effect of infrared radiation. Also heat
fluxes were measured through different insulation thicknesses
and for different roof temperatures. It was found
that a radiant barrier such as aluminum foil can reduce the
heat flux significantly.
Experimental results were compared to a Three-Region
approximate solution developed at Oak Ridge National
Laboratories (ORNL). The model was in good agreement
with experimental results.
Citation
Katipamula, S.; Turner, W. D.; Murphy, W. E.; O'Neal, D. L. (1985). Influence of Infrared Radiation on Attic Heat Transfer. Energy Systems Laboratory (http://esl.tamu.edu); Texas A&M University (http://www.tamu.edu). Available electronically from https : / /hdl .handle .net /1969 .1 /6841.