A HOFOR employee descending into a chamber at the harbour, Source: State of Green

Seawater cools a third of all Copenhagen's hotel rooms

Seawater cools a third of all Copenhagen's hotel rooms

Given climatic trends, we’ll be hearing more and more about district cooling systems, in line with heating ones

Copenhagen counts with a district cooling system, which is efficient and much more environmentally friendly than using air conditioners. The key resource to that system is free and widely available in the Danish capital – it’s seawater.

Although district heating as a service has been available since the beginning of the 20th century in Copenhagen, district cooling is a much more recent invention and addition, with the cooling station being established in 2008. Seawater is pumped from the Copenhagen harbour and then transferred through a closed-loop system.

This also frees up space in the buildings

The Greater Copenhagen Utility (HOFOR) supplies both heating and cooling in Copenhagen. District heating is delivered as a public supply service, but district cooling is a business run on normal commercial terms.

During the winter, it’s supplied for free, if needed, however, during the summer, compressors are also used thus there’s some electrical consumption involved. The experts, however, claim that this reduces power consumption by 40% compared to air conditioners.

What’s more, the system is designed in a way that frees up space in the buildings. Air conditioners removed from the roofs make it possible to create gardens or community spaces there, for example.

Hotels in the Danish capital are among the main customers of the district cooling system. As of 2023, approximately 8500 hotel rooms have been equipped with the innovative method to lower indoor temperatures. This represents about one-third of all hotel rooms in the city.

With the trends towards increasing temperatures in Europe, the demand for this kind of service is expected to grow, which is why it’s good to think not only about fossil-free energy production but also about fossil-free cooling production.

According to HOFOR, it helps reduce CO2 emissions by 70%.

In addition to Copenhagen’s hotels, several banks, museums, and department stores also use the attractive remote cooling solution.



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