Coolgardie safe

Overview

A Coolgardie safe is a cupboard with panels of wet hessian on its sides. Water is fed to the cloth, and as it evaporates it draws heat from the air inside. Food stored inside stays cooler than the air outside.

The principle is evaporative cooling, the same one used in clay pot coolers. Its effect depends on dry air and some movement of air through the wet panels.

Origin on the goldfields

The safe is credited to Arthur Patrick McCormick, a contractor in Coolgardie, Western Australia. The town was remote, and food was scarce and expensive, so keeping fresh food from spoiling and from scavengers was a priority. The cupboard was named after the town where it was made.

Museum records place its common form in the 1890s. Commercial examples were made later in other states: Museums Victoria holds a Trafalgar model made by W. J. Rawling in South Australia around 1915, credited to McCormick's design.

How it works

Water wets the hessian panels. When air moves through the wet cloth, the water evaporates, and the energy it takes from the air cools the cupboard. A shaded position and a steady breeze help it work.

The feet of the cupboard were usually set in a tray of water to keep ants away.

Limits

The cupboard's cooling is modest and weather-dependent. In humid or still air it does little, and in cold weather it is not needed. Historical use does not establish a modern safe temperature for any food.

A modern version should be built with contemporary food-contact and cleaning choices, and tested against the local ambient temperature and humidity. Evaporative cooling is not a meat refrigerator.

Use today

Coolgardie safes were used widely until refrigerators became common, when food was kept cool with ice or salted and cured. Surviving examples are held in museums and collections, and the form remains a reference for low-power food cooling.