Fire Safety Concern on Open Kitchen in Small Residential Units of Tall Buildings

Open kitchens have been designed for many small residential units in tall buildings in Southeast Asia. This open design, without enclosing the kitchen with fire resisting walls has failed to comply with building fire safety codes in places like Hong Kong. Performance-based design was adopted to determine fire safety provisions. Gas cookers with flames are not allowed. Additional fire protection systems such as water mist suppression or dry powder systems have to be provided above the stoves, though studies on kitchen fire physical hazards with and without fire resisting walls were not reported in the literature. A survey on fire load density indicated that large amounts of combustibles are stored in small residential units. Experiments with electric induction cookers indicated that the cooking oil in a frying pan can be ignited within ten minutes. Fire would spread out from the open kitchen to burn up all stored combustibles in the residential unit to give a big fire. There are queries on whether such open kitchens in tall buildings are really safe when there is an accidental fire. Aspects of big open kitchen fires both with and without fire resisting walls in small residential units of tall buildings should be further explored. Fire dynamics must be applied to study the possibility of onsetting flashover upon igniting the cooking oil and burning adjacent combustibles. There might be new fire phenomena such as the air pumping effect of the plume and flame whirling motion in an open kitchen to give big disasters. Full-scale burning tests should be carried out to confirm identified scenarios; to justify the model predictions; and to observe any new physical fire phenomena. Performance of the specified suppression systems including water mist and dry powder suppression systems in big fires must be evaluated.