SWAC (Sea Water Air Conditioning) is an innovative and ecological Air Conditioning technology which uses a renewable source of cold water. It is particularly fitted to Islands in the tropical belt as they represent an important cooling need (A/C electric consumption can add up to more than 30% of the total electric consumtion) and only a few kilometers away, deep in the ocean is a vast unused reservoir of cold water. The idea of SWAC is to link them together. Sea water is pumped and cools down the distribution loop with the help of a heat exchanger.
Other sources are appropriate for this use :
- Oceans : Difference in density with temperature results in a stratified profile where the deeper you go and the clder the sea water. It is unsually below 7°C around 1000m below the surface.
- Lakes in temperate areas : cold water naturally stays at the bottom (depth of about 50m). The alpine Lakes are a very suited area for SWAC implementation.
- Cold water surface currents (As in Stockolm’s downtown AC system)
Depending on the cooling need, even surface temperature water can be put to good use for other means, see paragraph “Beyond air-conditioning”.