Mayekawa NH3 heat pump uses lake water to heat Swiss hotel

By Silvia Scaldaferri, May 02, 2013, 12:10 2 minute reading

80% of the heat for the Badrutt Palace Hotel, situated in the heart of the Engadin of the Swiss Alps, is produced by a Mayekawa heat exchange system which uses water from Lake St. Moritz. The system was installed when the hotel projected an overhaul of its existing fossil-fueled heating system in 2006. The project has resulted in a savings of approximately 475,000 liters of heating oil per year, translating into approximately 1200 tons of CO2 emissions saved.

Differing from traditional heat pump systems extracting heat from the air or the ground, this high-performance ammonia HP system by Mayekawa uses lake water as a heat source. By way of a pipeline at the bottom of Lake Moritz, 4°C water is transferred to a heating plant center and released into a separate circuit at 70°C. The water suction inlet is located 50 meters (approx. 165 feet) from the shore and 10 meters (approx. 35 feet) below the lake’s surface. Maximum suction capacity is approx. 4000 liters of water per minute which corresponds roughly to the flow rate of a small stream.

The cycle is complete when the cooled-down water at 1°C is conveyed back into the lake via a second conduit, water quality unchanged. The total conduit is more than 300 meters (approx 985 feet) from the shore and the pipes about 35 meters (approx 115 feet) beneath the water’s surface.

Mayekawa ammonia heat pumps can act as standalone units using a waste water or geothermal heat source, or can be integrated into an existing refrigeration system as a heat recovery application.

Main features and advantages:
  • Uses natural refrigerant NH3 (ammonia)
  • Screw and reciprocating packages available
  • Ammonia and water heat source available
  • Produces hot water up to 85°C
  • Cuts energy costs and reduces CO2 footprint
  • COP ranges from 2.5 to 6 (depending on application conditions)

Making up the energy difference

The Badrutt Palace Hotel is located a chilly 1750 meters above sea level (approx 5750 feet), has a total of 10 floors and nearly 200 rooms to heat. During peak energy usage, three modern oil-fired boilers stand ready for use, and, in addition, excess heat from the hotel’s waste incinerator is redirected efficiently. Waste heat from the flue gases are also recovered and fed into the heating system. All together, these sources supply around one quarter of the hotel’s energy.

Results

The Badrutt Palace Hotel is located a chilly 1750 meters above sea level (approx 5750 feet), has a total of 10 floors and nearly 200 rooms to heat. During peak energy usage, three modern oil-fired boilers stand ready for use, and, in addition, excess heat from the hotel’s waste incinerator is redirected efficiently. Waste heat from the flue gases are also recovered and fed into the heating system. All together, these sources supply around one quarter of the hotel’s energy.

About Mayekawa / Mycom

Mayekawa is one of the world leaders and global suppliers of industrial cooling & freezing systems. Mayekawa has been promoting Natural Refrigerants ever since its creation. Over 30.000 famous MYCOM compressor blocks are integrated in air conditioning, chilling, cooling, freezing and heat pumps installations in over 120 countries.

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By Silvia Scaldaferri

May 02, 2013, 12:10




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