ENERGIES: largest seawater air conditioning system in world commissioned in Tahiti

Thanks to the swac, the cold waters of the depths will refresh the hospital center of French Polynesia. The hospital plan to save at least 2.5 million euros of electricity a year thanks to this technology.


At forty meters above the ground, shortly after midnight this Saturday, November 6, Maciek Buraczynski clears the last nut. With its team specializing in height work, it has just connected the huge swac pipes – for Sea Water Air conditioning, naturally cold water air conditioning – and the air conditioning network of the French Polynesia hospital located in Pirae, Northern town of Tahiti. The building site is over. In a few weeks, after the tests, it is a renewable energy that will cool down the hospital.

The three swac pumps will draw one million liters on time, more than 900 meters deep in the Pacific Ocean. Because the temperature is much cooler than in the surface: the water is at 5 ° C. By connecting its air conditioning system to this 3.8 km long underwater pipe, the hospital will no longer use electricity to produce cold. What should allow the ultramarine community to reduce its electrical needs by 2% on the island of Tahiti, the most inhabited by the Overseas Community.

No question, however, to inject seawater into the dozens of kilometers of hospital’s piping. “The SWAC allows, at very low energy consumption, to bring the cold seawater and the fresh water from the air conditioning network, through a titanium millefeuille, explains David Wary, engineer of the AIRARO local company, a project management assistant. This exchange system does not require a mixture of water: seawater, after transmitting its refrigeration [unit of measurement of the amount of cold], is rejected in the Ocean without having been altered. “

Special conditions needed

Swac main handicap: its price. Thirty-one million euros for it, “depreciable in ten to fifteen years, with a lifetime estimated at thirty years,” according to Cathy Tang, project manager serving the energies of French Polynesia. This green energy is already used in two Polynesian hotels: in Bora-Bora, where the swac has been, however, down for several years, and to Tetiaroa, to air conditioning the ultra-luxurious eco-hotel The Brando. But this is the first time a public structure funds a Polynesia swac, and that of the hospital is more powerful than the other two meetings.

“The air conditioning of the hospital was so far about nine million kilowatt hours consumed each year to produce ice water for 1,600 air conditioning units, with 84 air treatment plants For the operating blocks, the Réa, the scanner, the whole hospital “, explains Teumer Mu, head of the technical services of the hospital center. It considers that the hospital will save more than 2.5 million euros of electricity a year … or more in a few years: other extensions under construction, such as the Cancer Institute, will also be fed by this system to their OPENING.

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/Media reports.