Wood

Since wood swells as it absorbs water, and contracts as it releases water, both it's moisture content and dimensions are influenced by the relative humidity of the surrounding air.

Damp wood is heavy and difficult to work whilst dry wood will warp and split.

The desired moisture content of both softwoods and hard woods is dependent to some extent on the type of wood, and on the intended use.

Moisture content of wood

The aim of dehumidification in wood stores for the wood products industry is always to attain a constant indoor climate so that the supplier of wood products can guarantee the high, consistent quality of its goods for end-customers. Recusorb works with heat recovery and can use steam, electricity, gas or hot water as regeneration power source. For companies with access to hot water, it can be especially beneficial that Recusorb works with heat recovery, to save energy-costs.

Wood moisture content is equal to the weight of water contained in the wood divided by the oven-dry weight of the wood, expressed as a percent. A wood moisture content of 8 to 10% is achieved at 40% to 55% relative humidity. Heated wood stores have an unpredictable effect on the wood's moisture content as temperature influences the relative humidity - albeit uncontrolled.

A desiccant dehumidifier maintains the store relative humidity within the desired range irrespective of the store temperature. The climate will remain constant and the wood will be maintained at the correct moisture content.

Suppliers wishing to guarantee the quality of their wood product should consider using desiccant dehumidifiers in their stores. If wood is stored in a humidity controlled single skin PVC building, there is the added advantage of low air infiltration rates (low moisture gains), so operating costs are kept to an absolute minimum.