CAR PARK VENTILATION
CAR PARK ANALYSIS
CFD analysis to evaluate the performance of car park ventilation systems for vehicle pollutant control, smoke extraction to assist the fire service in the event of a fire and the pressure acting on escape doors
The analysis evaluates the ventilation systems compliance during Pollution Control and Smoke Clearance in accordance with BS 7346-7 and BS 9999
MECHANICALLY DRIVEN SYSTEM
Early evaluation of a massing model of the proposed development allows for mitigation to be avoided and the building itself can be designed to limit the impact on the local micro climate. With analysis at this stage mitigation could be avoided at a later stage or post completion.
NATURALLY DRIVEN SYSTEM
With a detailed design even the small variation in facade design can influence the wind safety at ground level. Analysis can highlight any mitigation measures required before completion that allows more flexibility with design options.
NATURALLY DRIVEN WITH ASSISTANCE
After a development has been completed,the impact of the local micro climate may not have been fully considered at planning stages. To ensure a safe space to the local area, evaluation can help with possible mitigation measures.
Evaluate the performance of the ventilation system during Pollution Control operational mode.
Through detailed modelling of the car park geometry with the jet fan configuration, the system can be evaluated against the criteria set out in BS 7346-7:2013 and Building Regulations (Approved Document B (England and Wales), Scottish Buildings Standards Technical Handbooks (Scotland),Technical Booklet E (Northern Ireland).
Fire safety is an important elements of any design, with car parks there is an empathise on the performance the system, whether that be mechanical or natural, in relation to their performance in the case of fa fire.
With Computational fluid dynamics modelling, Smoke Clearance can be evaluated with smoke being simulated within the space. CFD analysis provides a valuable insight with easily identifiable issues detected and presented visually to help understanding. This process ensures a ssytem that performs to established criteria as well as ensuring a more optimised set up.
The modelling is evaluated againist the crtierea established within BS 7346-7:2013 and Building Regulations.
TRANSIENT FIRE ANALYSIS
As well as cold smoke air flow evaluation, a simulated fire can also be analysed within the car park.
Through the simulation of a car fire within the car park, the temperatures and smoke distribution can be analysed to establish many factors including where smoke could move inside and outside of the car park and the pressures exerted on escape doors.
Through using a transient model of the fire within the car park, the pressures exerted across the doors for escapes routes can be analysed.
With a detail model of the car park as a base, the escape routes can be detailed and we can analyse the pressure exerted against them. The pressures are then compared to the 50 N threshold that is outlined within the British Standard BS 7346-7:2013.
WIND ASSISTED SYSTEMS
A major concern with naturally driven or assisted designs for car park ventilation relates to the impact of local microclimate conditions. Wind speeds and direction can vary dramatically, as well as the need to consider the local buildings to a development, all of these issues lead to a concern about the MSVS performance.
With CFD analysis, the surrounding site and local wind conditions can be simulated to evaluate the system performance as well as highlighting any problematic areas. This information can provide reassurance that a design will work.
Another factor to consider with natural system is where the smoke may travel when existing the car park. Wind could direct the flow a hot smoke toward neighbouring buildings that may cause damage. With a model of the local site these issues can be identified and demonstrated in an easy to understand method to reassure stakeholders.