Grundfos equipment contributes to energy saving heating and cooling.
At first sight the 85 meter tall, black luxury hotel does not look green, but the Crowne Plaza Copenhagen Towers sets new standards for sustainability and low energy consumption.

The Crowne Plaza Copenhagen Towers is not just an architectural landmark and a world class luxury hotel. It is a visible demonstration of comfort walking hand in hand with sustainable solutions, and since the opening in 2009, it has received a vast number of awards and recognitions for its path-breaking innovative construction. Among these was the Skål International 2010 EcoTourism Award for the project World’s Greenest Hotel.

Advanced energy storage
An exceptionally low energy consumption in the hotel’s heating and cooling systems reflects the green approach. Thanks to one of the world’s most advanced aquifer thermal energy storage (ATES) systems, the total annual energy consumption is extraordinary low. The consumption for central systems for heating, air-conditioning, and ventilation is only 51 kilowatt-hour per square meter for heating, air conditioning, and ventilation.

The ATES system, located in the basement of the Crowne Plaza, covers up to 60 per cent of the building’s total cooling need, and as a “free” cooling process, it supplies cold groundwater for guest room cooling during the summer. The cold groundwater circulates through an exchanger that cools water in the hotel’s hydronic air-conditioning system. In this process, the groundwater heats up and subsequently is saved in another well, so that it can be utilized for room heating during the winter.

Short payback time
The extra investment in the ATES system really pays off. It has a projected payback time of between six and seven years. This means that the Crowne Plaza Copenhagen Towers is greener as well as more profitable than its competitors in the long term.

Combined with a variable airflow volume (VAV) ventilation system, the ATES system ensures individually cooling, heating, ventilation of guest rooms, and lobby as well as conference facilities in accordance to the present demand. The systems performs 4.1 megawatt cooling and 2.4 megawatt heating, and ensure particularly low costs for air-conditioning and heating, compared with other hotels.

Efficient Grundfos pumps
All HVAC pumps in the building are from Grundfos. They contribute to considerable reduced energy consumption in all systems for air-conditioning and heating. The pumps are very energy efficient on their own, and all of them are equipped with frequency converters in order to make them able to adapt variations in flow requirements – and thus further contribute to energy savings.

The hotel’s projected energy consumption is 51 kilowatt-hour per square meter for heating, air- conditioning, and ventilation. For an average European four-star hotel, the energy consumption is about 300 kilowatt-hour per square meter. The two figures can however not be compared directly, as the figure for the Crowne Plaza Copenhagen Towers – contrary to the average figure - does not include decentralized devices, connected to plugs. The size of this part in the average figure is not known.

The calculated payback time for the ATES system is six to seven years.

Author: Jens Nørgaard, Senior Manager, Building Services Applications