Moisture
and Relative Humidity
-
Relative humidity (RH) is the term that we use to
describe the amount of water vapour in the air at a specific temperature.
-
With low RH, air has a greater capacity to
absorb moisture causing objects to dry out
-
With high RH, objects will tend to absorb
water from the air.
- recommended RH for a general archival collection
where paper-based materials comprise the dominant medium is somewhere
between 40% to 45%.
- The acceptable annual range recommended by the
Canadian Council of Archives, taking into consideration Canadian climate
changes over a year, is between 35% to 55% RH
- Below 35% and above 55% spells trouble!
Next