The need to find a method for cooling a house in a hot climate is nothing new. With the use of systems for heating and cooling, Melbourne residents have demonstrated their willingness to look for effective solutions. Throughout history, there has been a range of methods and approaches for keeping cool.
How older civilisations kept cool
The ancient Egyptians hung dampened reeds over their windows and they also placed pots filled with water in their passageways. The ancient Romans used internal courtyards, sometimes with gardens and pools of water, to promote a flow of cooling air through their buildings.
In the Middle East, wind catchers were a common architectural technique that would improve airflow through buildings and help keep them cool. Sometimes these were used in conjunction with water pools, where the air would flow through the wind catcher down over the water where it would cool, before flowing through the rest of the property.
Mud bricks were a commonly used material for building houses and these act as a very effective insulator. They were often made with straw to help keep the integrity of the brick and to improve their resistance to weather. This ensured also that they were very good at keeping the heat out. In recognition of this, mud bricks are used quite regularly now in designs that are utilising passive specialised heating and cooling techniques.
In Malta, they recognised that by building their houses with very thick walls and small windows they were able to reduce the amount of heat that came into the property during the hot day. In Greece, they painted their properties white to reflect a lot of the heat that came from the sun. In Spain, fountains and pools as well as deep set windows helped to reduce the impact of the summer sun.
Modern cooling solutions in Melbourne
For specialised heating and cooling, Melbourne has always been looking for the best solutions. To deal with the hot summer sun we experience, there were some design innovations such as large sleeping porches and wide overhanging roofs that protected the windows from the sun. In addition, the windows were often made small to reduce the amount of heat that would be able to flow into the living environment. The large overhanging roof on the verandah provided protection from the sun, but also made it possible to keep doors and windows open even when it was raining.
For houses in Australia that had external verandah space, there was the development of the sleep out. Many houses in summer would tend to retain heat inside, particularly on nights when there was little air flow so that it would be cooler outside of the building. The idea behind this was to create a space on the verandah where people were able to sleep in the cooler night air while still having the protection of the roof. It was often surrounded by flyscreen mesh walls to keep insects away or was semi-enclosed with thin walls and windows to provide greater privacy. It was possible to hang hammocks or to have sleeping beds in the space.
One of the largest access points to a house were the doors. In Australia, there are many flyscreen doors that have been developed so that it is possible to leave doors open and at the same time preventing the entry of flying insects, particularly flies. Some of these had spring mechanisms attached to make them self-closing. Some of them had special metal frames built in to make them security doors as well. In other places, they used long strings of beads or long strips of coloured materials that would hang down from the top of the doorway. This allowed easy access and the flow of air while still preventing the entry of flies without the need for an opening and closing screen door.
The development of secure windows that could be opened as well as be fitted with a flyscreen ensured that it was possible to have windows open during the evening and the night when air temperatures had dropped. By having them open on different sides of the property, it was possible to have a cooling flow of air through the house.
Inside the house, people would use block-out curtains on the windows. This would prevent the heat from being able to flow into the living environments during the day. These curtains could then be drawn in the evening and the windows opened to allow the cooler air to flow through.
It was identified that hot air rises, so to help reduce the heat levels in living areas the ceilings were made higher in some houses. This is quite effective in allowing the cooler air to flow through the lower parts of these rooms.
With the development of apartment blocks in the city, these were sometimes provided with balconies that could offer some protection for the living areas from the sun. In addition, some buildings took advantage of external blinds or awnings over windows that were able to reduce the impact of the sun.
Ancient cooling techniques are still being used
Some modern buildings are now being designed to take advantage of the cooling techniques from ancient architecture.
In Rajasthan, a modern architecture company developed a property with traditional exterior styling that provides valuable cooling protection for the building, open courtyards within the building to promote airflow, and a large pool of water on the lowest level that helps to cool the air through evaporation while providing a decorative element. It includes a double skin for exterior walls based on a traditional building method that provides a buffer from the heat. The use of these techniques substantially reduces the need for the use of modern air conditioning systems.
In Dubai, an engineer has taken the traditional wind tower design and is combining it with modern refrigerant technology to create a zero-energy cooling system.
Australian architects have been using passive cooling elements in designs for many years, particularly in the northern parts of our country. In Melbourne, there has been a recognition of the benefits of doing this to reduce the need for the use of cooling systems and minimise the costs of keeping a house cool in summer.