Confined Space Training Certificate Ventilation Systems and Equipment 3

Question 1

What is a significant hazard of using a petrol-engined generator to power ventilation equipment near a confined space?

Accepted Answer

Carbon monoxide from the generator exhaust may be drawn into the confined space

Answer

The generator may overheat and shut down, interrupting ventilation

Answer

The noise level may prevent verbal communication with confined space workers

Answer

The generator may produce insufficient power to run ATEX-rated fans

Question 2

What is the purpose of the pre-entry ventilation period (purging) before entering a confined space?

Accepted Answer

To replace the existing confined space atmosphere with fresh air before workers enter

Answer

To dry out moisture inside the space and prevent slip hazards

Answer

To test whether the ventilation equipment is functioning correctly

Answer

To cool down the confined space temperature to a comfortable working level

Question 3

How should ventilation ducting be routed to maximise its effectiveness inside a confined space?

Accepted Answer

Route ducting to direct fresh air to the furthest and lowest points of the space

Answer

Keep ducting as short as possible and terminate it at the entry point only

Answer

Route flexible ducting along the highest parts of the space to avoid trip hazards

Answer

Avoid using flexible ducting — rigid steel duct must always be used

Question 4

What is the key difference between 'supply' and 'exhaust' ventilation systems in a confined space?

Accepted Answer

Supply (push) systems blow fresh air in; exhaust (pull) systems extract contaminated air out

Answer

Supply systems use electrical power while exhaust systems use compressed air

Answer

Supply systems are used for horizontal spaces and exhaust systems for vertical spaces

Answer

Supply systems require ATEX certification but exhaust systems do not

Question 5

For lighter-than-air gases such as methane, where should the exhaust duct inlet be positioned to extract them most effectively?

Accepted Answer

At the highest point of the confined space near the roof

Answer

At the lowest point of the confined space near the floor

Answer

In the centre of the confined space at mid-height

Answer

At the worker's breathing zone level throughout the space

Question 6

What must be checked about ventilation ducting before and during confined space operations?

Accepted Answer

That ducting is free from kinks, damage, or blockages that could restrict airflow

Answer

That the ducting is painted the correct safety colour for the hazard type

Answer

That the ducting is constructed from rigid steel and not flexible material

Answer

That the ducting length does not exceed a maximum of 5 metres

Question 7

Which of the following statements about natural ventilation in confined spaces is correct under UK guidance?

Accepted Answer

Natural ventilation must not be relied upon as the sole means of ventilation where an atmospheric risk exists

Answer

Natural ventilation alone is sufficient for the majority of routine confined space entries

Answer

Natural ventilation is acceptable as the sole method in spaces shallower than 2 metres

Answer

Natural ventilation is the preferred method when flammable gases are a known hazard