Terracotta Warriors cry out for clean air(4)

Gu said there are still some difficulties to overcome in existing museums like the Emperor Qin Shihuang's Mausoleum Site Museum.

Besides the Terracotta Warriors, the pit itself is a relic too, because it shows evidence of a fire, which according to legend was started by Xiang Yu, the king of Chu, after he beat Qin's army. "So it offers tough challenges for scientists to install an air curtain that both covers the whole area and keeps the completeness of the tunnels," Gu said.

Gu added that reforming the existing museum facilitates is not his first goal.

"The best application of an air curtain is to add it into the design of a new museum, so that the air curtain becomes a part of the whole, which both protects the relics and ensures a comfortable exhibiting environment," he said.