Rated 2.5 of 5.
Level of importance:
Rated 2 of 5.
Level of validity:
Rated 4 of 5.
Level of completeness:
Rated 1 of 5.
Level of comprehensibility:
Rated 3 of 5.
|ScienceOpen disciplines:||Engineering, Architecture|
|Keywords:||Preventive conservation, Historic buildings, Built environment, Micro-environment, Air movement, Mould|
The paper analyses data from continuous monitoring of air temperature, relative humidity, and velocity behind books in bookshelves and in the space in front of the shelves at three locations.
The driving forces behind air movements behind the books are seen as the result of differences in air temperatures influencing air density and the activities in the buildings housing the historic bookshelves including movements by visitors, renovation works and opening of doors.
The paper presents a simple model assumed to predict air velocities that is demonstrated to have some prediction capability but lacks precision and inclusion of important parameters such as surface temperatures of walls behind bookshelves and more precise information about openings between space and hidden environments.
The analysis would benefit from more precise modelling of boundary layers and buoyancy taken from more comprehensive fluid dynamic and heat transfer theory. The analysis would also benefit from more precise modeling of wall surface temperatures and information about outdoor temperatures during measurements.
Mold will normally start growing in the range 70-75 %RH. Absolute humidity measured as water weight per weight of dry air will without sinks and sources be constant in air flows being heated and cooled. Analyses of water content based on temperature and relative humidity would also be relevant in the available data. Moisture content of the cold exterior walls could be at equilibrium with somewhat higher relative humidity than measured in the air and be at higher risk of mold growth.
My thinking is that increased air flows behind the books in bookshelves may not be sufficient to prevent mold growth on cold outer walls but may increase the temperature of the books and their margin to mold formation.
Paper would benefit from more precise modeling of air flows, assessment of wall temperatures and inclusion of absolute humidity in the analysis.