Confined Space Training Certificate Ventilation Systems and Equipment

Question 1

What is the primary purpose of mechanical ventilation in a confined space?

Accepted Answer

To dilute or remove hazardous atmospheres and maintain safe oxygen levels

Answer

To reduce humidity levels and control temperature inside the space

Answer

To eliminate the requirement for gas monitoring equipment during entry

Answer

To provide cooling for workers during physically demanding tasks

Question 2

Which type of ventilation involves blowing fresh air directly into a confined space?

Accepted Answer

Supply (forced) ventilation

Answer

Exhaust ventilation

Answer

Natural ventilation

Answer

Recirculation ventilation

Question 3

What type of fan must NOT be used in a confined space where flammable vapours may be present?

Accepted Answer

Non-ATEX-rated fan that can generate sparks

Answer

Axial flow fan with variable speed control

Answer

Centrifugal fan with a large diameter impeller

Answer

Backward-curved fan with a polyester casing

Question 4

Where should the exhaust duct outlet be positioned when using extraction ventilation in a confined space?

Accepted Answer

At least 3 metres away from the entry point to prevent recirculation

Answer

Adjacent to the confined space entry point to monitor output

Answer

Directed back downward into the confined space for recirculation

Answer

Immediately above the confined space opening at roof level

Question 5

What is the approximate normal oxygen content of fresh air at sea level?

Accepted Answer

21%

Answer

18%

Answer

23%

Answer

25%

Question 6

Below what oxygen level is the atmosphere considered oxygen-deficient under UK confined space guidance?

Accepted Answer

19.5%

Answer

23.5%

Answer

21.0%

Answer

17.0%

Question 7

What must be carried out BEFORE workers enter a confined space after mechanical ventilation has been applied?

Accepted Answer

Conduct atmospheric monitoring to confirm the space is safe to enter

Answer

Remove ventilation equipment from the entry point to allow free access

Answer

Reduce the ventilation flow rate to conserve energy during entry

Answer

Verify that the ventilation fan is the correct colour for the hazard type