Combustion Efficiency Testing Flashcards

What is the maximum acceptable smoke number on the Bacharach scale for a kerosene-fired appliance?

Answer: 0 (zero)

For kerosene (Class C2) appliances, the maximum acceptable Bacharach smoke number is 0. Any smoke production from a kerosene burner indicates a combustion problem requiring investigation. Gas oil burners allow a reading of 0-1.

What effect does altitude have on oil burner combustion?

Answer: Higher altitudes have less oxygen, requiring air adjustment for correct combustion

At higher altitudes, air density and oxygen content are lower. This means less oxygen is available per volume of air drawn in by the fan, potentially requiring adjustment of the air settings to maintain correct combustion ratios.

When performing a combustion analysis, what does 'CO air free' (COaf) mean?

Answer: The CO reading corrected for dilution, showing what the CO would be with no excess air

CO air free (COaf) is a calculated value that removes the diluting effect of excess air from the CO reading. It gives a truer picture of the combustion quality, as high excess air can mask dangerously high CO production.

What is the standard test for checking the integrity of the combustion chamber?

Answer: Visual inspection for cracks, distortion, and deterioration with the burner removed

The combustion chamber is visually inspected with the burner removed, using a torch to check for cracks, warping, erosion, and deterioration. Any damage could allow combustion gases to escape, creating a carbon monoxide risk.

What does a continuously dropping CO2 reading during a test indicate?

Answer: A possible air leak into the flue system or an opening developing in the combustion path

A dropping CO2 reading suggests air is entering the system and diluting the flue gases. This could be from a flue joint opening up as it heats, a crack in the combustion chamber, or a deteriorating flue seal.

In what order should combustion adjustments be made on an oil burner?

Answer: First check and set pump pressure, then adjust air settings while monitoring CO2 and smoke

The correct sequence is to first verify pump pressure (which determines the fuel flow rate), then adjust the air band while monitoring CO2, smoke number, and CO readings to achieve the optimal combustion settings.