In a typical construction environment, the walls and ceilings must accommodate fixtures and utilities that pass through. It is in these necessary areas where the risk for air pressure loss is the greatest. Arcoplast set out to discover just what could be expected from their fiberglass composite panels when integrated with such utilities. The test, performed by Technical Safety Services, Inc. set out to find out the pressure decay of an Arcoplast panel featuring a 12” metal duct and an electrical box. A standard panel with no perforations was used for reference.

TSS mounted the 6mm cement core panels to a special Plexiglass enclosure using a foam rubber gasket, grease and c-clamps. It was pressurized to 1000 Pa for each test and recorded once per second from there.

The final results showed some surprising results. The plain, standard panel showed an average drop of 1.6 Pa per minute during decay testing, and the control test of 59 sealed minutes from. But, in testing the sealed additions, air pressure actually increased within the enclosure. The metal duct saw an initial pressure of 1,065.6 Pa, but ended up with 1,143.7 Pa. The pressure, on average, increased 1.3 Pa per minute. Even the small electrical box showed an increase of 0.2 Pa per minute. It was concluded, that since the Arcoplast panel on its own does such a superb job of holding in pressure, that the small “heat transfer” differences from the metal duct and the electrical box actually pushed the internal pressure up.

Two other tests were also performed. In the initial control, the standard panel spent 59 minutes building air density from atmospheric pressure at a rate of 0.6 Pa/min on its own. And in the final test, the electrical box’s plug was removed at the 60 second mark. Where it had held strong until that point, it obviously stood no chance to a large gapping hole and quickly lost pressure.

The Public Health Agency of Canada document, Laboratory Biosafety Guidelines: 3rd Edition (2004), requires that a Containment Level 4 room exhibit a maximum of 12.5 Pascal (Pa) per minute pressure drop at 500 Pa over a 20-minute period. Also, given the dimensions of the test enclosure, the maximum rate of allowable air leakage at 1,000 Pa is 0.0056 standard cubic feet per minute (scfm).