OFTEC Combustion Efficiency Testing

Question 1

What is the primary instrument used to measure combustion efficiency on an oil-fired appliance?

Accepted Answer

Electronic flue gas analyser

Answer

An electronic flue gas analyser measures CO, CO2, O2, flue gas temperature, and calculates combustion efficiency. It is the essential tool for commissioning and servicing oil-fired appliances to OFTEC standards.

Question 2

What is the recommended CO2 reading for a kerosene pressure jet burner operating correctly?

Accepted Answer

10-12%

Answer

A correctly adjusted kerosene pressure jet burner should produce CO2 readings of 10-12%. Below 10% indicates excess air (wasting heat), while above 12% indicates insufficient air (risk of CO production).

Question 3

What is the maximum acceptable CO reading in the undiluted flue gas for an oil-fired appliance?

Accepted Answer

50 ppm

Answer

The maximum acceptable CO reading is 50 ppm in undiluted flue gas. Readings above this indicate incomplete combustion and potential danger. The appliance should be adjusted or taken out of service if this cannot be achieved.

Question 4

What does a smoke number of 0 on the Bacharach scale indicate?

Accepted Answer

Clean combustion with no visible smoke or soot

Answer

A Bacharach smoke number of 0 indicates clean, complete combustion with no measurable soot. For kerosene burners, the target is a smoke number of 0. For gas oil, a reading of 0-1 is acceptable.

Question 5

What is the Bacharach smoke test used to measure?

Accepted Answer

The level of soot particles in the flue gases

Answer

The Bacharach smoke test draws a measured volume of flue gas through a filter paper. The resulting soot stain is compared against a numbered scale (0-9) to assess the level of incomplete combustion.

OFTEC Practice Test

OFTEC Practice Test

OFTEC Combustion Efficiency Testing