Passive or Active microclimate control system
Micorclimate-controlled museum display showcases are much more conservational than traditional display cases.Around the museum objects in the air-tight museum display cases and cabinets,if the humidity and temperature is too high or too low,the objects will be possibly damaged so it is necessary to keep a relative constant humidity and temperature in the display volume.Microclimate within display area are controlled with invisibly-installed passive or active environment controlling system so a perfect and protective internal display and storage environment at constant humidity and temperature comes into being.
A.PASSIVE MICROCLIMATE CONTROL SYSTEM
As a passive humidity control system,silicon gel dehumidifier like Prosorb or Artsorb in the steel silicon gel tray will blance the relative humidity through absorbing or releasing moisture.The humidity change will accordingly bring a change on temperature.The microclimate chamger is completely discrete from above internal display space and exchange air through invisible air pores.The precision of active microclimate control system can be ±5%.
Prosorb is a preferred silica gel ideally suitable to stabilizing relative humidity within museum display cases or storage cabinets.With longer life span and the exceptional ability of absorbing surpassed moisture and desorbing absorbed moisture,Prosorb can maintain a relatively constant humidity within narrow margins between 40%–60% RH(40%-60% RH is an ideal humidity for museum display cases and cabinets) for long time.Prosorb usually come with loose beads or rigid plastic cassettes.Cassettes are constructed of sturdy polypropylene and vapour permeable non-woven polyester fabric,and are filled with loose beads.Re-conditioning the RH-value of a prosorb cassette can be done easily by size change.
Advantage of Prosorb
*Free of chlorides-PROSorb contains no lithium chloride, as some other products do (Lithium chloride is a chemical - salt, potentially harmful to many metals. This salt can be transferred to metals in dust or by human touch). PROSorb consists of 97% SiO2 and 3% Al2O3.
*Low abrasion-PROSorb beads produce less dust than other silica gels (abrasion < 0,05 weight-% according to MIL-D).
*High bulk density-1 kg PROSorb only needs a volume of ca. 1,5 l (much less than some other silica gels).
*Long term stability-PROSorb maintains the greater part of its capacity well beyond the 2-5 years when other silica gels have lost a large portion of their capacity.
*Economical-PROSorb is much cheaper than the other products sold for the same purpose.
*Temperature dependency-PROSorb is conditioned in relation to temperature. PROSorb reacts in the same way organic materials do. Therefore there will be no, or little, transfer of water vapour between organic materials and PROSorb if the temperature changes. Under fluctuating temperatures this property protects wooden objects and other organic materials from swelling or shrinking: The conditioning indicated on the labels refers to 20°C. At 10°C the conditioning of the cassettes will be around 1 - 1,5 % RH lower, at 30°C around 1 - 1,5 % RH higher.
Dimensions: L 335 mm, W 110 mm, H 44 mm.
Content: 950 g beads
Consumption:One or more cassettes per cubic metre of air volume are required,up to circumstance application
Dimensions: L 335 mm, W 110 mm, H 24 mm.
Content: 500 g beads.
Consumption: One half-size cassette will be sufficient for 0,7 m3,up to circumstance application
B.ACTIVE MICROCLIMATE CONTROL SYSTEM
EBC series of miniclimate units are preferred to be used for climate control in museum display cases, storage cabinets that are classified as air and steam tight.At about the same size as a large shoe box, the combined dehumidifier and humidifier unit is easily hidden from view in a separate compartment within the display showcase. The museum showcase or cabinet is connected to the miniClima EBC using two flexible hoses, forming an airtight recirculation system. Air is extracted from the case into the EBC where it is conditioned before being fed back into the cabinet.