Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.
The tracer gas technique is used to experimentally
measure the infiltration of warm air into walk-in coolers during
its nominal operating conditions. The tracer gas samples
captured before, during, and after the infiltration process are
collected through sampling probes inside and outside the
cooler. The infiltration rate can be calculated from this data.
The transient nature of the infiltration rate that is captured in
this approach signifies the shortcoming of the existing
methodologies currently practiced in industry. It is found that
the infiltration rate is a function of the temperature gradient
between the inside and outside air, relative humidity, and the
void volume in the cooler. It is also demonstrated that it is
possible to derive a closed form equation based on the
experimental data that can replace the current equations.