概述

Excessively dry air

Dry air absorbs humidity from objects, their weight is reduced and they contract. In the case of humid air, it is the other way round. Climatic fluctuations thus keep the objects in permanent movement and sooner or later a crack appears on the canvas or the color gilding chips off the baroque sculpture. Stabilization of the relative air humidity helps avoid tension in the material texture of the exhibits, the Building Climate Institute emphasizes.

The preservation of enshrined cultural artifacts generally requires a constant indoor climate which is defined within relatively tight limits [2]. This climate has to be technically created. The air requires humidification — at least periodically. The values reached are measured using measuring systems. Nowadays, due mainly to lease agreements, international indoor climate values of between 50 and 55 ±5% RH and 20°C are required [2]. The American ASHRAE standard formulates corridors for the indoor climate in even greater detail — from the narrowest AA to D. The narrowest climate corridor specifies RH = ±5% and T = ±5 K as long-term tolerance with seasonal adjustment. Positive from a conservational viewpoint is that there is a slow, seasonal adjustment of the indoor climate to the outdoor climate which lies within these limits.

Climate Fluctuations

The external climate and the relative air humidity show significant seasonal fluctuations. In winter, the RH is sometimes extremely low. In summer during rainfall, 100%. The external space and inner areas are more or less closely related at all times. This means that a change of the external climate is also noticeable indoors

Comfort

Correctly humidified rooms feel warmer and more comfortable, especially in colder climates where heating systems are required.

敏感木製品

每種材料都對其環境氣候有具體要求。金屬，石材，帆布，油，木材，皮革，紙張或象牙不同於濕度和溫度波動的不同。在紙張，木材，帆布或羊皮紙上工作是最敏感的物體之一。我們紙的主要原料是植物纖維，紡織纖維和木漿。這些是強烈吸濕的材料。通過吸收室內濕度和釋放材料濕度，它們遵循環境中的所有濕度波動。這些交換過程需要通過木細胞的尺寸的變化來擴張或收縮材料。

This is expressed by warping of parchment or paper, or by tears or bubbles on panel and canvas paintings or on color-gilded sculptures. On papers, humidity fluctuations lead to a displacement of soluble components such as the ink. Specialist terms here are ink corrosion and copper corrosion.

Fabrics, photographs, metal and stone

在紡織對象,過分低空氣濕度dvances the fragility of the tissue. In photographic objects, substrates and binding agents become fragile and brittle in environments with low RH. Comfortable in a climate of between 20 and 60% RH, stone and ceramic can tolerate a low air humidity.

Learn more about humidification for museums...