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

Petrol and diesel generators produce carbon monoxide in their exhaust fumes, which can be drawn into the confined space by the ventilation system and rapidly create a potentially fatal atmosphere.

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

Pre-entry purging replaces the existing atmosphere within the confined space with fresh air to dilute and reduce contaminants to safe levels before any worker enters.

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

Ventilation ducting should reach the extremities and lowest points of the confined space to ensure fresh air circulates throughout the entire work area, eliminating any stagnant pockets.

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 ventilation blows fresh air into the confined space while exhaust ventilation draws contaminated air out; both approaches have specific applications depending on the nature and location of the hazard.

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

Lighter-than-air gases like methane rise and accumulate at the highest points of a confined space, so extraction must be from the top of the space to remove them effectively.

Confined Space Practice Test

Confined Space Practice Test

Confined Space Training Certificate Ventilation Systems and Equipment 3