Saturated salt solutions in showcases: humidity control and pollutant absorption

Abstract The sustainable, passive climatisation of display cases using saturated salt solutions is rarely applied nowadays. These adjust the atmospheric humidity to specific deliquescence relative (DRH) salt. Practical problems like risk spilling or ‘creeping’ salts can be overcome. DRH suitable does not depend significantly on temperature. Solutions were Oddy-tested check for corrosive emissions acids corresponding anions. Only magnesium chloride failed in accordance with thermodynamic calculations HCl vapour pressure. absorb water-soluble pollutants aldehydes from atmosphere, as has successfully been demonstrated formaldehyde chamber experiments. alkaline potassium carbonate solution only dissolves and but also reacts them chemically. Research needs further study absorption are outlined. A revival would make museum displays more sustainable.