In: Mechanical Engineering
A walk –in cooler 3 m by 5 m by 3m High equipped with twelve 0.6 m by 0.6 m triple-glass doors is used for general purpose storage in a drive-in market (heavy usage). The walls are insulated with 50 mm of expanded cut cell polystyrene, and the cooler is to be maintained at 2°C. Compute the cooling load in kilowatts based on a 16-h operating time if the ambient temperature is 25°C.
The overall heat transfer coefficient values for glass and polystyrene are taken from the literature. The area of glass is calculated. The total area is calculated and then remaining area of polystyrene is then calculated. The cooling load can then be calculated as the sum of the heat coming from the glass walls and that from the polystyrene walls. The obtained cooling load is in Watts and it is then converted into kWhr.