Abstract
This paper presents an outline of a model which can be used to estimate the concentration of blowing agents emitted from the foam insulation into the cavity of a domestic refrigerator. The basic assumption of the model is that blowing agent is emitted from the foam via a diffusion process and finds its way into the refrigerator cavity via holes and slots (for feed-throughs, shelves, etc.) which are cut in the plastic liner. The concentration of blowing agent inside the refrigerator decays asymptotically with time and depends on the diffusion coefficient and initial concentration of blowing agent in the foam, the number and surface area of holes through the plastic liner, whether or not the foam is adhered to the plastic liner, and the air exchange rate for the refrigerator.
The model calculations indicate that, under normal operating conditions, the blowing agent concentration inside the refrigerator is very low, typically, parts per billion by volume. It is believed that the assumptions on which the model is based are conservative, i.e., the model over-estimates the concentration of blowing agent in the refrigerator. The sensitivity of the calculated concentrations to these assumptions is also discussed.
Get full access to this article
View all access options for this article.