Pressurisation systems for smoke and fire ventilation
A pressurisation system for smoke and fire ventilation should meet the recommendations of Approved Document B and BS EN 12101-6 "Specification for Pressure Differential Systems".
A pressurisation system consists of three main components: Supply Air (where air is injected into the area that is to be protected), Pressure Relief (to avoid overpressure when doors are closed) and Air Release (air and smoke is released from the adjoining fire area). Combining these elements creates a positive pressure difference that prevents lobbies and staircases from filling up with smoke.
Contact Colt for more detailed information on pressurisation systems and what the requirements are for your project.
FAQs
What is a pressurisation system?
Pressurisation systems supply clear air to a protected space in order to increase the pressure in that space – this additional pressure prevent smoke from entering the area.
When do you need a pressurisation system?
In the UK, pressurisation systems are commonly used when the traditional natural or mechanical smoke ventilation solutions are not suitable or compliant. It may also be used as an alternative to discounting a staircase when planning and sizing evacuation routes.
The latest draft of BS 9991 is also recommending pressurisation for single stair residential buildings over 18m, but this is only in draft format at the moment and may be subject to change.
What are the requirements of a pressurisation system?
The main requirements for pressurisation systems in England can be found in BS EN 12101-6: 2005 (soon to be replaced by BS EN 12101-6 & 13: 2022). These standards explain how to design a pressurisation system for all types of building - there are 3 key requirements that need to be met:
- The correct pressure in the stair core when the doors are closed
- The correct air velocity across certain doors when they are open
- A maximum door opening force must not be exceeded
The key things to keep in mind when designing a pressurisation system to meet all the requirements are:
- How will the pressurisation supply air get in and how will it be kept smoke free?
- How will the difference in airflow between the closed door and open door condition be managed?
- How will the air movement be maintained? If an air velocity is to be achieved, then an air release path will be needed
- Leakage calculations will be required to estimate how much air will be lost from the protected space
- Space available for the equipment
Contact Us
Get in touch today to discuss your project and allow our expert team to find the right solution for your building.