State of Ohio Computer Center

State of Ohio Computer Center, a humidified facility, exhibited symptoms of condensation problems from wall weeping and water discharge in cold weather to water and frost built up on the inside surfaces of the window framing and glazed insulated glass units.  The original wall design incorporated three distinct vapor retarders: foil-backed drywall, plastic sheeting, and foil-faced insulation batts.  An initial assessment of the problem indicated that control of airflow into the wall was inadequate, and an air barrier was needed.

To verify the initial assessment, instruments were implanted in the wall to monitor behavior over several winter months.  A computer-controlled data acquisition system took hourly readings of temperature, relative humidity, and differential air pressure at several layers through the wall profile.  Additionally, two trial repairs were installed and monitored.

The assessment confirmed that movement of the interior humidified air into the wall was the cause of the condensation problem.  The program also indicated that the first repair alternative involving complete reconstruction of the wall from the interior side provided better condensation control than the second repair alternative involving upgrading the air barrier.  The monitoring program made it possible to determine that the differences in behavior between complete reconstruction and simply upgrading the air barrier were small and would occur only under the most severe climatic conditions.

RRJ designed the required repairs and provided full-time on-site observation and repair construction administration services.