Specifications

The Need
• Higher outdoor air requirements in ASHRAE 62-2 have increased
the amount of ventilation air, making the need for humidity control
more critical than ever
• When working with or storing wood products, the humidity levels
must be kept in the correct range, otherwise excess moisture will
cause wood to swell and expand in width and thickness and low
moisture will cause shrinkage.
– Cabinet and door manufacturers must maintain between 40%-
50% RH.
– Musical instrument stores need to maintain 50% RH, excess
moisture can cause swelling and popping
• High and low humidity can deteriorate paper products.
– Libraries and archival collections must maintain between 30% -
50% RH