Works of art constantly under the action of unfavorable microclimate. This action results in chemical and physical changes in the materials, which cause irreparable damage. Changes in temperature and humidity are one of the main causes of this destruction. The difficulty of creating the required climatic conditions is explained by several causes. To determine the conditions of temperature and humidity required for conservation, and to create them with the aid of heating, ventilation and air-conditioning, it is necessary to examine the building and determine the degree to which all the factors influence the temperature-humidity conditions in the entire building.