COPENHAGEN, Denmark (May 29, 2013) – Opened in 2009, the four-star Crowne Plaza Copenhagen Towers stands 85 meters tall and boasts a shiny black facade. Even more impressive is that this feature of Denmark's capital city skyline sets new standards for sustainability and low energy consumption.

The winner of the 2010 EcoTourism Award for the World's Greenest Hotel, the Crowne Plaza relies on Grundfos Blueflux® technology to work in synchronicity with the hotel's demanding heating and cooling system. The resulting combination is exceptionally low energy consumption, according to Jens Nørgaard, application Manager for Grundfos Commercial Building Services.

To keep energy consumption and CO2 emissions as low as possible, the hotel insisted on the most innovative energy technology throughout the building. One of the world's most advanced aquifer thermal energy storage (ATES) systems is located underground in the basement of the Crowne Plaza. Cold groundwater is used for cooling the guest rooms during the summer. The heat rejected from this process is reused for heating during the winter.

The ATES system delivers cooling and heating for the building’s high performance HVAC system. This system represents one of Denmark’s first groundwater-based cooling and heating systems. The hotel’s total annual energy consumption is a remarkable 51 kilowatt hours per square meter for heating, air conditioning, domestic hot water and ventilation.

No active refrigeration is required while the groundwater is circulated through the hotel's hydronic air conditioning system. By reversing the flow, the warm groundwater is also available for heating during the winter season.

During the heating season the chiller is turned into a heat pump. The groundwater is cooled and returned to the aquifer’s cold well. The water is returned at a temperature similar to the temperature of the untouched groundwater.

The ATES system is designed to be extremely compact. The entire system—without distribution equipment—occupies only 8 x 10 meters. To maximize energy savings and high heating temperatures, ammonia is used as a refrigerant.

The two chillers are fitted with frequency-controlled screw compressors, which enable the chillers to adjust the capacity to the actual load with the same efficiency. Chillers rarely run at full capacity, and it is important that the efficiency is high. The groundwater pumps and all the other pumps are provided with frequency converters to allow the pumps to adapt to flow requirement variations.

Both the energy efficient ATES system and a network of solar cells are part of the hotel’s green profile.

Interesting Facts
Several other initiatives are in place to reduce CO2 emissions and to ensure that the hotel achieves its aim of sustainability:

  • The hotel’s guests literally get to feel the green profile of the hotel. Everything from the shampoo bottle to the toothbrush is made of corn and potato starch. The revolutionary, organic material looks and feels like plastic but is both recyclable and biodegradable. The products contain no parabens or allergenic substances.
  • No hotel information is printed. All information for the hotel guests is delivered electronically via an interactive TV screen information system that is intuitive and similar to web pages.
  • All components in the hotel’s IT infrastructure—switches, routers, access points and laptops—are chosen based on energy consumption and recyclability. The packaging is also taken into consideration.
  • The kitchen is—wherever possible—built with the latest induction technology. Induction technology turns on and off instantly. It heats immediately and only where it is needed. This drastically minimizes heat waste in the kitchens.
  • The handling of waste products from the kitchen is another substantial investment in technology and environment. All food waste in the hotel is grinded and stored in a tank in the basement. The waste is transported to a biogas plant and the remains from this process are used to fertilize farmland.
  • Food is delivered only three times a week instead of once or twice every day. The aim is to reduce the carbon emission from the transportation of goods and the collection of packaging. Food deliveries are, as much as possible, only accepted from companies located within a radius of 300 kilometers.
  • The traditional company car has been eliminated. Crowne Plaza has bought two electric Citroën C1s, which are mainly used by the hotel’s sales team. The hotel’s staff is encouraged to use public transportation because no employee parking is available at the hotel.
  • All guest rooms are ventilated with variable air volume (VAV). The air volume is automatically adapted according to temperature and occupancy.

Grundfos delivered all pumps for the building’s air conditioning, heating and water boosting. The following products were supplied specifically for the ATES system:

  • 3 pcs. NB 65 200/219 end-suction pumps with external frequency converters; these are the primary pumps in the buildings hydronic heating system
  • 3 pcs. NB 125 315/290 end-suction pumps with external frequency converters; the primary pumps in the buildings hydronic cooling system
  • 2 pcs. NBE 65 250/254 end-suction pumps with internal frequency converters, dedicated for the chillers condenser circuits
  • 2 pcs. NBE 100 200/195 end-suction pumps with internal frequency converters, dedicated for the chillers’ evaporator circuits
  • One TPE 80 340/4 in-line pump with internal frequency converter serves as the primary cooling tower circuit; one TPE 80 370/4 in-line pump with internal frequency converter serves as the secondary cooling tower circuit