Branch: Hospitality
Ibis Hotel Basle, Switzerland
Project
To avoid the lengthy approval procedure for conventional refrigeration/air conditioning plants (> 3 kg HFC refrigerant) in Switzerland, the contractor already decided at the development stage to use the existing district heating available from Industrielle Werke Basel (IWB) for chilled water generation via absorption cooling. Within the IWB supply area, heating systems must be connected to district heating. The IWB and Canton Basle support air conditioning by district heating with attractive tariffs and allowances to compensate for the higher investment costs in comparison to conventional refrigeration.
Task
The main objective of the planning was to realise a lean, economic and sustainable heating and air conditioning system for the 2 star economy hotel. The dehumidification of the air played an important role in the air conditioning because of the climatic conditions (River Rhine flood plain) in Basle. Legal requirements regarding noise control and visual impact were determining factors in designing the cooling tower installation on the roof of the hotel.
Solution
- Hotel rooms: individually operable ceiling integrated circulation air cooling and heating units
- Manually adjustable dual line system with zero energy band
- Basic ventilation with dehumidification, double air change
- District heating connection for 220 kW
- District heating connection cooling for 150 kW
- 1 Yazaki WFC-SC-30 absorption chiller, nominal refrigeration output 105 kW (max. 140 kW), volume flow rate varying from 30 - 100 %
- 1 adiabatic cooling tower, with 250 kW nominal capacity, with particularly quiet, speed adjustable fans and speed reduction at night
- Buffer storage of 2,000 litres for chilled water circulation
- Capacity control (30 to 100%) for demand orientated refrigeration
Challenges
- Basle City Authority legal requirements regarding cooling tower installation (noise control, visual impact)
- Hydraulic and control engineering overall design for absorption refrigeration plant
Special characteristics
The district heating provider supports absorption chillers with the following tariffs and benefits:
- 3.25 Rappen/kWh (corresponds to approx. 2.15 Euro-Cent/kWh) district heating combined with absorption chillers operation during 5 summer months
- 3.5 Rappen/kWh (corresponds to approx. 2.32 Euro-Cent/kWh) for absorption refrigeration machine operation during 7 summer months
- Assumes 10 percent of the investment costs of the absorption refrigeration plant
- Assumes the costs for the extra design costs for an absorption refrigeration plant
Project participants
Client: Balhotel AG, Basle
General contractor: Bauengineering.com AG, Basle, Switzerland
Building services design: Bogenschütz AG, Basle, Switzerland
Supply, commissioning and maintenance of the absorption chiller: Walter Meier (Klima Schweiz) AG, Schwerzenbach, Switzerland
Technical data of the installed YAZAKI absorption chillers
- YAZAKI Li-Br absorption chiller, Model WFC-SC 30
- 105 kW refrigeration output (max. 140 kW)
- Hot water: 88 °C to 83 °C (inflow min. 70 °C / max. 95 °C; Volume flow rate varying between 30 and 100 %)
- Cold water: 12.5 °C to 7 °C
- Cooling water: 31 °C to 35 °C
- COP: 0.7 to 0.78
