Design of smoke exhaust systems for hotel corridors: choosing between natural and mechanical smoke exhaust
I am fire protection expert Alexander Li. The design of smoke exhaust systems for hotel interior corridors is a core element of fire safety and directly affects the safety of occupant evacuation and the effectiveness of fire smoke control. Based on years of engineering experience, this choice requires comprehensive consideration of building height, corridor length, structural conditions, and code requirements; an incorrect decision may lead to smoke exhaust failure or cost waste. Below I will analyze this in conjunction with GB50016-2014 (2018 Edition) and practical project experience.
First, the basis for choosing between natural smoke exhaust and mechanical smoke exhaust mainly comes from Section 9.2 of GB50016. Natural smoke exhaust is applicable to corridors with openable exterior windows or smoke exhaust openings, requiring the window opening area to be no less than 2% of the corridor floor area (Article 9.2.2), and the exterior windows should be located at both ends or on the side walls of the corridor to facilitate the natural outflow of smoke. For example, in a 6-story hotel with an interior corridor 30 meters long and exterior windows on both sides, we give priority to natural smoke exhaust because it is low-cost, simple to maintain, and compliant with the code. However, note that natural smoke exhaust is affected by wind direction and outdoor air pressure and has relatively low reliability; if the corridor length exceeds 60 meters or effective exterior windows cannot be provided (such as in underground corridors), mechanical smoke exhaust must be used (Article 9.3.1).
The design of mechanical smoke exhaust systems shall comply with GB50261-2017 "Code for Construction and Acceptance of Automatic Sprinkler Systems" and Section 9.3 of GB50016. The mechanical smoke exhaust rate is calculated based on the corridor area and is generally no less than 60 m³/h·m² (Article 9.3.2), and smoke exhaust openings, smoke exhaust fans, and a makeup air system must be provided. For example, in a high-rise hotel project in Shenzhen, the interior corridor is 80 meters long and 2.5 meters wide and cannot be provided with natural smoke exhaust, so we designed mechanical smoke exhaust: smoke exhaust rate = 80×2.5×60 = 12,000 m³/h, using one smoke exhaust fan, with one smoke exhaust opening provided every 30 meters (spacing ≤30 meters, Article 9.3.3), and coordinated with the automatic sprinkler system. During construction, we strictly tested the smoke exhaust fan air volume and pressure in accordance with GB50261 requirements to ensure system reliability.
Practical case: In the renovation of a four-star hotel in Beijing, the interior corridor is 45 meters long, and the original natural smoke exhaust windows were blocked by the curtain wall. After evaluation, we changed to mechanical smoke exhaust, adding smoke exhaust fans and ducts, increasing the budget by about 150,000 yuan, but avoiding the risk of natural smoke exhaust failure. Another case: In a resort hotel in Hangzhou, the interior corridor is only 20 meters long and has exterior windows on both sides, so we retained natural smoke exhaust, requiring only regular maintenance of the window opening devices, thus saving initial investment.
Summary: For hotel interior corridor smoke exhaust systems, natural smoke exhaust should be given priority (when conditions permit), but the window opening area and location requirements must be met; if the corridor is too long, has no exterior windows, or is subject to structural constraints, mechanical smoke exhaust must be used and strictly designed in accordance with the code. In actual projects, I recommend conducting simulations in combination with the building plan and fire compartments during the preliminary design stage to avoid later rework.
The above are reference opinions. The actual project conditions still need to be further comprehensively evaluated and implemented in combination with specific operating conditions, site conditions, and other factors.