Valsana’s game changing ice battery
The Tschuggen Hotel Group has been climate neutral since 2019. We minimise our CO2 emissions through continuous investment into cutting-edge technology and we offset our remaining footprint with carefully selected carbon-credit projects in Switzerland and the developing world. These include work with myclimate and extensive climate protection projects, such as the re-wilding of bogs near Tourbières des Ponts-de Martel and helping protect the habitat of mountain gorillas in Rwanda
When we opened The Valsana Hotel in 2017 we put sustainability at the heart of the project. This continues to be a major focus for the hotel and the ethos has been embraced by our staff. Our Executive Chef Arkadiusz Rachwal takes great care to ensure that all products are produced sustainably, and the Head of Housekeeping Sandra Marques ensures that only environmentally friendly and certified cleaning agents are used.
A central element of the sustainable processes at the Valsana Hotel is the hotel’s ice battery. This incredibly innovative temperature converter is used to power the hotel. Coupled with a sophisticated heat recovery system, the Valsana does not need oil or electric heating.
We spoke to Mr Meier, the Head Technician who is responsible for maintaining ice battery and asked what a temperature converter actually does and how it works.
What does a temperature converter actually do?
I am a member of the technical staff here. Because the hotel has such a highly complex technical system and these technologies are really diverse and complicated, monitoring the heat recovery systems and the ice battery takes a lot of time.
Which temperatures are converted?
There are a lot of sources of heat that we can recover here at the hotel. We get a large part of the waste heat by recovering waste water. The waste water with excess energy comes, for example, from showers, the spa area, the laundry and the kitchen. Waste water has an average temperature of about 15 – 22 degrees Celsius. After the heat recovery of the waste water, the temperature drops up to four degrees before it finally runs into the sewage system.
The supermarket on the ground floor runs a lot of refrigerators and multideck refrigerated cabinets, and we also generate a lot of waste heat in the hotel kitchen through the refrigeration points. All this energy is fed back to the ice battery. In the summer, part of the hotel (the restaurant and kitchen) can be cooled by the ice battery, resulting in a pleasant climate.
How does the ice battery work?
The three hotel buildings are heated using the hotel’s own heat recovery system and geothermal probes, which feed into a large latent heat storage unit (the ice battery). Heat pumps draw their energy directly from this unit, which looks a bit like a large water tank. The tank holds 860,000 litres of water. Four hundred metres of internal pipes 1.5 m high were installed in this large basin, with a water-glycol mixture flowing through the pipes. This is connected to the heat pump circuit. When the heat pumps extract a large amount of energy, the water in the pipes freezes to form an ice block. The waste heat from all heat recovery systems is fed back into the water tank to thaw the ice. If more waste heat is generated than energy withdrawn, the ice melts and the water heats up to 15°C. The water can then be cooled again and the heat used.
Just imagine we were all temperature converters ourselves: where exactly could we convert temperatures in everyday life?
If we all had an ice battery in the cellar, which is of course still a pipe dream, we could use all the heat we generate. Whether from washing clothes, cooking or showering – wherever heat is generated, it can also be reused.
What is the best and most exciting part of your job?
The most exciting part is the monitoring and improvement of the system. Even with such a highly complex system, there is still plenty to be optimised. For example, I think about where we could gain even more heat or how we could perhaps channel the heat more efficiently. For me, it’s a great feeling that I spend time improving the energy balance of the establishment.
What are the acceptance levels with regard to the system?
There is something very special about being able to say you work on a unique system. We have something that hardly anybody else has. We are pioneers and that makes me proud. Universities and also companies visit us regularly to have a look at the system. We are always very pleased that there is such great interest and are happy to share our knowledge. I have even had contact with a member of staff from the castle of the Prince of Lichtenstein and with the Arosa Academy.
You can find out exactly what an ice battery is on our Valsana Green Tour. For us, it is not only important to act sustainably, but to share our experience and knowledge with our guests. We hope this approach helps further promote sustainability in the wider hospitality issue because sharing knowledge means doubling knowledge for all. When it comes to tackling climate change that can only be a good thing.