November 2014 - Amazon's Seattle office buildings will recycle waste heat from a nearby data center in the Westin Building to warm its new campus. This recycling of heat is called a hydronic heat system. The system transfers the heat from the data center through water piped underground to the Amazon buildings. The water is then returned to the Westin Building after it's cooled down to help cool the data center. The system will be the first of its kind in the country and will save Amazon about 80 million kWh of electricity over 25 years.

News Article - Amazon's new campus to be heated with recycled energy

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