Swedish Hospital Cools Itself With Winter Snow

Sundsvall, Sweden – A hospital in central Sweden has found a clever way to stay cool in summer: it saves snow from winter and uses it months later.

The Sundsvall Regional Hospital collects snow during the cold months and stores it in a large pit. The pit is 140 metres long and 60 metres wide – about the size of a football field. It can hold up to 60,000 cubic metres of snow, which is roughly 40,000 tonnes.

But how does the snow last through the hot summer? The answer is wood chips.

In spring, workers cover the snow with a thick layer of wood chips. This layer, about 20 centimetres thick, acts like a blanket. It keeps the snow cold and stops it from melting too fast. Without this cover, all the snow would disappear by mid-June.

When summer comes, the hospital pumps meltwater from the snow pit through pipes into the building. The cold water cools the hospital rooms. Then the warmer water goes back to the snow pit to melt more snow, and the cycle continues.

The system worked so well that in its first year, it provided 93% of the hospital's cooling needs. The rest came from traditional cooling machines.

This helped the hospital save a lot of electricity. The hospital now uses over 90% less energy for cooling than before. It has also cut its carbon emissions by 290 tonnes per year.

"The hospital needed to replace its old cooling machines," said Jan Lindberg, an energy controller at the hospital. "Instead of buying new ones, we chose a smarter solution".

The idea is not completely new. People in ancient Greece and Japan used to store ice and snow for cooling long before modern fridges were invented.

Today, other countries are looking at the Sundsvall example. Similar systems are already being used in Japan and at an airport in Norway.

"It is a very simple technical solution," Lindberg said. And it proves that sometimes, the best ideas are the oldest ones.