3963 -- Use of Passive Radiation Barriers in Ventilated Attics PDF

The model developed is a one-dimensional transient approximation of the various heat transfer processes taking place in a ventilated attic. Along with the attic insulation, an attic radiant barrier system (ARBS) is investigated; this is composed of two highly reflective foil surfaces that sandwich in between them a layer of air bubbles. The main purpose of the barrier is to reduce the net radiant heat transfer flow that eventually reaches the ceiling as a cooling load. The attic space is assumed to be actively ventilated by the discharged exhaust air from an evaporative cooler that is cooling the living space. The model is a fully implicit one that does not reduce or simplify the nonlinear radiation terms. It also assumes that the air properties and the convective heat transfer coefficients are variables that have to be iterated on as part of the overall solution of nodal temperatures at each time step. Presents details of this model and its capabilities. The accuracy and physical behaviour of the model have been partially verified by running several numerical experiments.

KEYWORDS: year 1996, passive, foils, attics, heat flow, thermal insulation, cooling load, evaporative cooling, heat transfer coefficient, accuracy, air temperature, calculating, air, bubbles