Solar sauna set to multiply

Throughout the icy temperatures of this winter, there has been a small haven of warmth in Scottish higher education.

Tariq Muneer, lecturer in energy engineering at Napier University, has designed a solar-powered sauna on top of one of the campus buildings. Preliminary investigations have revealed positively balmy temperatures despite the gloomy conditions outside.

"It's very warm. I put some cactus plants in because no other plants would withstand the temperature," Dr Muneer said. "It can take two people lying down or three or four people sitting, and several of our technicians go there and relax."

The sauna has been built by Nor-Dan, a Norwegian window manufacturer, using high-tech triple-glazed windows with a special tin oxide coating that traps solar energy. Temperatures in the sauna are monitored hourly by research student Nasser Abou-Dahab. These show that for more than 180 days a year, the sauna's temperature will be over 60 degrees C, rising to a sizzling 80 degrees C in summer.

"We will continue measuring until next winter, and from those results, we will be able to build up mathematical models to design saunas in other parts of the country," Dr Muneer said. "If we can demonstrate that the sauna works in the northernmost major conurbation, then for the rest of the country, there's no problem."

The project is being funded by Nor-Dan and the Edinburgh findings will also be applied to southern Norway. The sauna should prove commercially viable, but because windows are the heat source and the sauna's warmth calls for minimal clothing, "it would have to be behind the house or in a remote area," said Dr Muneer.