Source: Web page  Canadian Consulting Engineer (http://www.canadianconsultingengineer.com/)
Is smoke in a shopping mall atrium more of a problem than we bargained for? Recent tests have been looking at the concerns.
In North America, it has generally been assumed that communicating spaces connected to an atrium or mall will be sprinklered and, as a result, the sprinklers will limit the size of a fire in the adjoining space. As a result, engineering design guides for smoke management systems such as National Fire Protection Association NFPA 92B1 have assumed that the smoke will have minimal effect in the atrium or mall space. The design guides, however, do allow for smoke management designs in which the smoke is allowed to spill into the atrium space.
With the introduction of performance-based designs for fire protection systems, there has been an increasing need to address the potential effects of smoke entering the atrium or mall. There have been concerns that smoke cooled by sprinklers in retail spaces connected to malls could travel downward, where it could endanger people evacuating the building.
In a recent joint study with the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the National Research Council of Canada investigated smoke movement from fires in sprinklered retail spaces linked to a mall.2 & 3 A large-scale test facility was set up to simulate areas of particular concern: a retail outlet on the second floor and a section of a pedestrian mall in a shopping centre. Because North American fire statistics indicate that approximately 90 per cent of fires in retail facilities activate four or fewer sprinklers,4 four sprinklers were used in the retail portion of the test facility. The mall portion of the test facility included a mechanical smoke exhaust system.
Tests were conducted to simulate retail fire scenarios with the fuel shielded from direct water spray from the sprinklers. The scenarios were typical of those that occur in retail stores in malls and included clothing and toys in boxes located in display units, and stored or displayed bulk goods, such as paper towels. | 