Derivation of a Model for the Calculation of Impact Loads of Air Pollutants to Paintings in Microclimate Frames

of gaseous pollutants on paintings installed in microclimate frames (mc-frames), and some examples of modelling results, is presented. The model can be used to study how basic design properties of microclimate frames, such as their air exchange rate, their volume and/or the inclusion of absorbers can affect the pollution fluxes to paintings inside the frames. The modelling indicated that a magnitude increase in air exchange rate from a low level of ~1 d-1 can significantly increase the impact of infiltrating pollutants, but will give only a small reduction in the potential impact of the small molecular weight organic acids (i.e. acetic and formic acid) that are emitted inside the frames. The reason for this is the small amount of pollutant removed by each single air exchange, as compared to the large internal emission and deposition fluxes of these gases.