Hotel Rotbuche: energy efficiency, ecology and comfort
On the former Weidmann site in Rapperswil-Jona, the client GJMO AG is building the third Moxy Hotel in Switzerland on around 500 square meters. The «Energie Zürichsee Linth» (EZL) is used for a sophisticated energy supply system.
The groundbreaking ceremony for the Hotel Rotbuche in Rapperswil-Jona took place in mid-February of last year. The three requirements and specifications for the energy supply and the energy system for the new hotel were clear: energy efficiency, ecology and comfort. In order to implement these requirements, geothermal probes were drilled as an energy source for the heat pump and a sustainable energy concept was developed in cooperation with Energie Zürichsee Linth (EZL). EZL will also operate and maintain the building technology as a contractor.
Heat recovery measures
"The reversible heat pump can be used to provide heat for heating purposes and for domestic hot water," explains Roman Fausch, project manager for energy services at EZL. In summer there is the possibility of cooling the building in an energy-efficient way using geothermal probes, according to the expert. If there is a high need for cooling, there is also the option of using cold from the reversible heat pump. Various heat recovery measures are also installed and, thanks to an intelligent control system, also regulated as required. "In connection with energy and sustainability, it is one of the most sustainable hotel projects that we have been able to plan and implement," says Stefano Ghisleni, general planner at Ghisleni Partner AG, based in Rapperswil, Zurich, St. Gallen and Zug.
At the Moxy Hotel Rotbuche, the natural heat comes from a depth of around 200 to 250 meters. The 23 probes, distributed over the entire construction area, withdraw 10 to 15 degrees from the ground. The heat is fed into the heat pump in the building using a carrier fluid and converted. This is how it gets into the hotel's heating and air conditioning system. The entire length of the geothermal probe control system is more than five kilometers.
Reduction of the room temperature by up to four degrees
Those responsible for the project emphasize that the basic need for room cooling in the warmer seasons in the Hotel Rotbuche can be covered with the environmentally friendly free cooling system. This means that the room temperature can be reduced by up to four degrees. This has a positive side effect: the dissipated heat is in turn temporarily stored in the geothermal probes and can be used for hot water preparation or in winter for heat supply. A photovoltaic system is installed on the roof to operate the heat pump. With around thirty percent, it should provide sufficient coverage to cover part of the electricity demand. "The moderately controlled balancing of heat and cold makes a continuous room climate possible without massive temperature fluctuations," says project manager Roman Fausch. The first guests will be able to feel this for themselves from the coming autumn. At this point in time, the new “Rotbuche” hotel with its 86 rooms is due to open. ■