System for elevator shaft ventilation and purging
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Solution Overview
Problem
In modern, energy-efficient buildings with airtight envelopes, elevator shafts often lack sufficient natural ventilation and smoke extraction due to the absence of direct connections to the outside, leading to inadequate air exchange and accumulation of smoke in the event of a fire, posing safety risks.
Innovation Solution
A ventilation and smoke extraction system with multiple strategically placed openings connecting the elevator shaft to the stairwell, equipped with fans and sensors, which are controlled to ensure air circulation and smoke removal, including a smoke extraction opening and an after-flow opening, to maintain operational safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If building envelopes are made airtight to improve energy efficiency, then energy loss is reduced, but natural ventilation and smoke extraction in elevator shafts deteriorate
Solution Approach 1:
The patent introduces a stairwell as an intermediary space between the airtight building interior and the elevator shaft. The stairwell receives fresh air from the building interior and passes it to the elevator shaft, enabling ventilation without compromising the airtightness of the main building envelope. This mediator approach allows indirect air exchange while maintaining energy efficiency.
Solution Approach 2:
The ventilation system is segmented into distinct functional zones: fresh air intake in the stairwell, air circulation through the elevator shaft, and smoke extraction paths. This segmentation allows the building envelope to remain airtight while creating dedicated ventilation pathways that do not compromise overall sealing.
2Reliability
If ventilation openings are added to improve air exchange, then ventilation effectiveness improves, but device complexity increases
Solution Approach 1:
The stairwell serves multiple functions: it acts as a fresh air intake zone, a circulation pathway, and a smoke collection area. By making the stairwell multi-functional, the system achieves effective ventilation and smoke extraction without adding separate dedicated structures, thereby limiting complexity increase.
Solution Approach 2:
The system utilizes natural buoyancy forces and pressure differentials created by elevator operation to drive air circulation and smoke extraction. The thermal buoyancy of hot smoke and the pressure changes during elevator movement provide self-driven flow, reducing the need for complex mechanical ventilation systems.
3Reliability
If fans are installed to force smoke extraction, then smoke removal effectiveness improves, but energy consumption increases
Solution Approach 1:
The fan system operates periodically rather than continuously, activating only when smoke detection triggers an alarm or when ventilation is needed. During normal operation, natural buoyancy and pressure differentials handle air circulation, minimizing fan energy consumption while maintaining smoke extraction capability when required.
Solution Approach 2:
The system changes operational parameters based on conditions: fans remain idle during normal operation and activate at high power only when smoke is detected or ventilation is urgently needed. This dynamic parameter adjustment optimizes the balance between smoke extraction effectiveness and energy consumption.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively ventilates the elevator shaft and extracts smoke during fires by utilizing controlled air flow between the elevator shaft and stairwell, ensuring the safety of elevator users and compliance with safety regulations.
Implementation Method 1
a fan (7) for conveying air from one of the areas, stairwell (4) or elevator shaft (2), and in the other of the areas, elevator shaft (2) or stairwell (4), is arranged in the region of at least one of the ventilation openings
Implementation Method 2
the air in the shaft moves naturally from the bottom to the top even without such ventilation openings and can contribute to the ventilation of the elevator car in the event of a malfunction and trapping people
Implementation Method 3
the same applies e.g. for cold smoke caused by a cable fire (smoldering fire). The cold smoke is only slightly buoyant over a short distance, then accumulates progressively in the shaft from level to level, but without any natural smoke evacuation
Data Source
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AI summary
A system for ventilation and/or smoke extraction in a building section (1) with a staircase (4) connecting several floors of a building directly adjoining the elevator shaft (2) with elevator car (3) that can be moved vertically is disclosed. wherein the staircase (4) and the elevator shaft (2) are in a common fire compartment of the building. This system is characterized by at least two ventilation openings (5, 6) connecting the elevator shaft (2) to the staircase (4), of which a first ventilation opening (5) is in a lower section of the elevator shaft (2) and a second ventilation opening (6 ) is arranged in an upper section of the elevator shaft (2), wherein in the area of at least one of the ventilation openings (5, 6) a fan (7, 8) for conveying air from one of the areas, stairwell (4) or elevator shaft (2) , in the other of the areas, elevator shaft (2) or stairwell (4) is arranged. This system allows reliable and safe ventilation or smoke extraction of the elevator shaft even if there is no thermal in the elevator shaft, as can be found in particular with the thermally insulated construction methods that are more and more common in modern buildings due to energy saving regulations.