Product Features

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The Daisy Positive Pressurisation Venting (PPV) Unit has been designed to provide an alternative approach to the natural 0.4m2 permanent ventilation within basement lobbies.

Section 2.47 of Approved Document B1 (ADB) identifies that where lobby ventilation is required for B1 means of escape, to protect the stair this can be achieved by natural ventilation or mechanical smoke control. Section 7.6 of the Smoke Control Association (SCA) Guidance document on Residential Buildings – 2015 provides guidance on how to meet the mechanical smoke control requirements using pressurisation. The BS9991:2015 references the SCA document as a source for further design guidance.

 

The PPV unit injects air into the protected lobby/stair to raise to a higher pressure to prevent the ingress of smoke from the car park.

The unit incorporates duty and standby fans, duty and standby fire dampers, smoke detector interface, single phase automatic electrical change over switch, controls, status LED and a volt free contact for 3rd   party monitoring. All the above is located within the decorative PPV enclosure box.

The system is operated by a smoke detector located on the car park side of the lobby door. The system continues to run until the smoke detector is reset.

 

Advantages

 

• PPV unit prevents smoke entering the stair.

• PPV unit occupies minimum space.

• The 0.4m2 expensive fire rated duct can be omitted.

• Low car park heights or stepping services around the duct are not a concern.

• The car park smoke clearance system does not need to be enhanced and can remain at 10 air changes per hour.

• Can be used with natural ventilated car parks.

• No expensive fire shutters required or control of inlet air paths.

• No expensive CFD justification of the lobby de-pressurisation.

• Robust solution that keeps smoke out of the stair core.

• Cost effective solution meeting the ADB & SCA Guide.