Photo: Ditte Valente
Photo: Ditte Valente
Photo: Ditte Valente
Photo: Ditte Valente

Roskilde: ChillCan putting a stop to lukewarm beer

Solar energy
Lukewarm beer is something any guest at Roskilde Festival would like to avoid. And the interest was almost overwhelming when four DTU students offered to teach guests at Roskilde Festival to build a foam-clad container named ChillCan, which is able to chill beer without using electricity. The students had planned three workshops, but after the first two on Sunday and Tuesday, the 55 kits they had brought were snapped up.

ChillCan applies the principle of 'evaporative cooling', which has been used for centuries to keep food cold using solar heat. The principle is well-known: If you stick a wet finger in the air, your skin feels cool when the water evaporates from the finger.

"Based on the experience gained last year, we have changed the design a little, so that it’s easier to build as well as being more robust and ‘festival-friendly’."
Magnus Held

ChillCan is made of a ventilation pipe with a lid clad with Rockwool and a lid clad with polyether foam. When the stone wool and foam are wetted and placed in the sun, the water starts to evaporate, and this process cools the inside of the pipe down to—at best—8 degrees below the ambient air temperature. The greatest effect is achieved in dry and warm weather.

Principles behind
“At our workshops in the camping areas, we gave the festival-goers the opportunity to build their own beer cooler with room for 38 beer cans. We also told them about the principles behind evaporative cooling and its perspectives,” says Magnus Held, one of the four DTU students behind ChillCan.

Like the rest of his team mates, Magnus Held is a BSc student at DTU, and he also visited Roskilde Festival in 2015 with a similar project called CoolBox.

Improved model
“Based on the experience gained last year, we have changed the design a little, so that it’s easier to build as well as being more robust and ‘festival-friendly’,” he says.

Their success was almost instant—at the first workshop on Sunday, the first 35 ChillCans were in use by festival-goers in a matter of only 30 minutes. The last 20 were quickly snapped up during the second workshop on Tuesday.