Out of the ordinary: Keeping clay soldiers (relatively) cool

The largest group of terracotta figures ever lent by China was on display at the British Museum until April 6, 2008. The Chinese government required the 20 warriors to be kept at temperatures of 22°C + 2°C and at humidity levels of 45% RH + 8%, a challenge, considering the variations in load presented by display lighting and up to 400 visitors every hour. Eight Moducel LKP air-handling units provided the air conditioning. Four units were identical fresh air units, equipped with filters and chilled air water-cooling coils, the other four units were identical recirculation units with filters, chilled water-cooling coils and humidifiers. These humidifiers pressurized the void beneath the exhibition floor with air supplied via floor-mounted swirl diffusers. Return air was drawn back through grilles around the perimeter enclosure via air-handling units including cooling, reheat coil and integrated Vapac electrode-steam humidifiers to achieve the necessary temperature and humidity control at all times.