Flue Gas Analysis Table

Introduction

See Flue Gas Analysis

Operation

Using a Flue Gas Analyzer or any meter designed to measure oxygen or carbon-monoxide, and taking the flue gas temperature and the temperature of the combustion air, the following Table can be used to determine combustion efficiency when operating on natural gas. The Temperature Column is the NET Difference between Flue Gas and Combustion Air Temperatures.

(Flue Gas Temp -minus- Combustion Air Temp)

Note that each fuel has its own characteristics. Therefore, these numbers are valid ONLY for natural gas.

Read Combustion Efficiency in the Column under the NET Temperature Difference, in the row for the measured O2% or CO2%.

Excess

Air %

Excess

O2 %

Excess

CO2 %

Combustion Efficiency at Net Temperature Difference

170F

220F

270F

330F

380F

430F

480F

530F

580F

0.0

0.0

11.8

86.3

85.3

84.2

83.0

81.9

80.8

79.7

78.6

77.5

4.5

1.0

11.2

86.2

85.1

84.0

82.7

81.6

80.5

79.3

78.2

77.0

9.5

2.0

10.7

86.1

84.9

83.8

82.4

81.2

80.1

78.9

77.7

76.5

15.0

3.0

10.1

85.9

84.7

83.5

82.1

80.9

79.7

78.4

77.2

75.9

21.1

4.0

9.6

85.7

84.5

83.2

81.7

80.5

79.2

77.9

76.6

75.3

28.1

5.0

9.0

85.5

84.2

82.9

81.3

80.0

78.6

77.3

75.9

74.5

35.9

6.0

8.4

85.3

83.9

82.5

80.9

79.5

78.0

76.6

75.2

73.7

44.9

7.0

7.9

85.0

83.5

82.1

80.3

78.8

77.3

75.8

74.3

72.8

55.3

8.0

7.3

84.7

83.1

81.6

79.7

78.1

76.6

74.9

73.3

71.7

67.3

9.0

6.7

84.3

82.7

81.0

79.0

77.3

75.6

73.9

72.2

70.4

81.6

10.0

6.2

83.9

82.1

80.3

78.2

76.4

74.5

72.7

70.8

68.9

98.7

11.0

5.6

83.4

81.5

79.5

77.2

75.2

73.2

71.2

69.2

67.1

119.7

12.0

5.1

82.7

80.6

78.5

75.9

73.8

71.6

69.4

67.2

64.9

145.8

13.0

4.5

82.0

79.6

77.3

74.4

72.0

69.6

67.1

64.7

62.2

179.5

14.0

3.9

81.0

78.3

75.7

72.4

69.7

67.0

64.2

61.5

58.7

224.3

15.0

3.4

79.6

76.6

73.5

69.8

66.7

63.5

60.4

57.2

54.0

Source: Table extracted from: Boiler Efficiency Institute, “Boiler Efficiency Improvement” by David F. Dyer and Glennon Maples, Copyright 1991.

More Information

Flue Gas Analysis

Oxygen Control

Combustion Air Control

Air Infiltration

Exhaust Draft Control

Flue Gas Condensers

Source: Table extracted from: Boiler Efficiency Institute, “Boiler Efficiency Improvement” by David F. Dyer and Glennon Maples, Copyright 1991.