A special technical installation, a sort of "artificial lung?, is at the entrance to the Scrovegni Chapel in Padua, Italy. The Chapel is a masterpiece in the history of painting in Italy and Europe in the 14th century. The special air-conditioned environment in the installation both purifies the air inside the Chapel and monitors its atmosphere continuously, in order to protect unique frescoes, some of the most important of all time. Groups of maximum 25 people wait at the door to the air-conditioned waiting-room to the chapel for 15 minutes, the time needed to stabilise the interior microclimate. They then enter the Chapel for another 15 minutes. Visits last a total of about 30 minutes. Automatic access doors open only once on entrance and exit, to allow stabilisation of the interior microclimate.
http://www.cappelladegliscrovegni.it