Smoke is the biggest killer in a fire, and an effective smoke control system is critical to preserving life and property. On the other hand, the pursuit of energy efficiency has led to increasingly airtight buildings, which poses new challenges in preventing overheating in common areas.

It is possible to address both smoke and environmental ventilation with one solution: for example mechanical shaft systems have seen great developments in recent years and are now capable of providing a highly effective performance while taking up less space than other types of shaft system.

The complexity of product and design standards relating to smoke and heat control systems, which are in constant evolution in response to regulations and experience in the field, may seem daunting, but help is at hand!

Here is a copy of the questions and answers from our recent webinar on smoke and environmental ventilation of multi-storey buildings using shafts, slightly edited for clarity.

During the webinar I introduced our new whitepaper on the subject, which you can download here.

There is also a recording of the webinar available here.

Ventilation is needed in atria for heat dissipation, to manage carbon dioxide and body odour levels, as well as for smoke clearance or smoke control. What better way to provide this than with a dual purpose day to day and smoke ventilation scheme?

There has been a trend towards fitting sprinklers in residential buildings, driven partly by the fact that this can enable the relaxation of other fire safety measures, including the extending of travel distances.

We are also aware of a couple of incidences where sprinklers have been used to justify omission of smoke control in residential corridors. We believe this to be a dangerous trend.

At our recent webinar on smoke and environmental ventilation of multi-storey buildings using shafts, we had a large attendance with many questions asked. Here you can see my answers to these questions, slightly edited for clarity. 

There is also a recording of the webinar available. Watching the recorded version will still enable you to claim CPD points.

Over the past couple of years it has become increasingly common for smoke and natural ventilation systems to be separated into different sub-contractor packages. For example, extract ventilators supplied by the roofing contractor, inlet vents by the glazing/cladding contractor, and wiring/controls by the M&E contractor.

In theory this makes sense because it may seem easier to procure the system in local packages. In practice it often doesn’t work.

At our recent webinar on car park ventilation, we had a large attendance with many questions asked. Here you can see my answers to these questions, slightly edited for clarity. 

There is also a recording of the webinar available. Watching the recorded version will still enable you to claim CPD points.

31st October 2014, 12.30-13.30 GMT

Join me as I present a free CPD webinar on Car park ventilation.

This webinar covers:

• An explanation of the basic legislative requirements and how these are achieved using impulse ventilation
• Application of impulse ventilation, both for carbon monoxide and for smoke clearance or smoke control

Why is energy efficiency not regulated in car parks?

In the last article in our series about designing smoke shaft systems, we discuss dual purpose systems.

Why dual purpose?

• Is your current project an apartment block?
• Are your corridors landlocked?
• Is the building well sealed and insulated? (of course it is)

And most importantly:

• Do you have hot water pipes running above the corridor ceilings?

If you’ve answered yes to all four questions you need a dual purpose system.

In the seventh and penultimate article in our series about designing smoke shaft systems, we discuss power requirements.

Natural shafts

One of the major advantages of natural systems is the very low power requirement. Most systems use 24V ventilators and run off standard 230V single phase supplies, with standby power provided by a battery back up unit which transforms and rectifies the incoming power to charge the batteries and drive the ventilators. The batteries then provide a temporary source of power in case of loss of mains supply. This is ideal for residential buildings that may not have a 3 phase supply.

In the sixth article in our series about designing smoke shaft systems, we discuss systems intended to compensate for extended travel distances.

How long can my dead end be?

How long is a piece of string? There is no definitive published answer to this. Approved Document B allows 7.5m in residential buildings. BS 9991 allows between 7.5m and 15m, depending upon the building and its fire precautions.

In the fifth article in our series about designing smoke shaft systems, we discuss noise and attenuation requirements.

Usage

When considering noise, shafts can be split into two types, those with and those without day-to-day comfort ventilation provision.

In the fourth article in our series about designing smoke shaft systems, we discuss the choice of the vents between the lobbies and the shaft.

Types 

The choice is short and sweet as there are only 3 basic types available:

• A smoke damper mounted behind a grille
• A bottom hung motorised flap
• A motorised fire door.

Seems a simple choice, but there’s more to it than aesthetics, as you’ll see.

In the third article in our series about designing smoke shaft systems, we look at the rooftop equipment.

Natural shafts

All you need is 2 or 3 roof ventilators

This bit can be short and sweet as all we need at roof level are 2 (or sometimes 3) roof ventilators – one at the head of the stair, one at the head of the shaft and, for residential buildings, sometimes one as an AOV to separately ventilate the top floor lobby to minimise the height above the roof of the top of the shaft.