In addition to the systems designed to operate with high pressure centrifugal and axial airmovers, specially designed unit exist that create even higher-pressure airflow. These units are specifically designed to force air into or out wall cavities or other interstitial spaces, or under flooring materials for efficient drying of otherwise inaccessible areas. This structural drying equipment is designed primarily for drying wet wall, ceiling, and other assemblies including complex flooring systems. These systems can be classified according to pressure ranges and by manner in which they handle airflow through ducting and attachments.
These systems have higher pressure capabilities and is necessary to overcome the resistance of small diameter air delivery systems, attachments, and the restriction of tight airspace’s where moisture can be trapped.
Attachments can be affixed to these systems for filtering, directing, and manipulating air.
Such manipulation could include utilising ducting and wall cents to direct air beneath floor systems with sleeper or flutes, and into wall or ceiling cavities.
Pressurisation can be positive, negative or both (i.e. push-pull). Attachments can include a system of panels or mats temporarily adhered to the top of wood panels can be influenced by the amount of actual pressure exerted on the flooring system. The greater the pressure and resulting airflow, the faster the moisture will be removed from beneath the flooring material. Positive-pressure systems carry many of the same risks as other airmovers in that they can spread contamination. When drawing moist air out of potentially contaminated cavities using negative pressure, an inline HEPA filter should be used to remove contamination before exhausting the air into the room.