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  Burner O2 Calculator for Air Temperature Changes  
  This calculator is for informational purposes only.  Use at your own risk. Burners should be adjusted only by qualified personnel.  Always consult with burner manufacturer before adjusting burner settings.  
   
  Centrifugal fans pass more air at cold temperatures than hot temperatures.  Accordingly for a given fan setting, the oxygen delivered to the burner will fall as the temperature increases.  Use this calculator to determine the value to which oxygen will fall: 1. Enter values in orange fields.  2. Read result in green field below.  3. The slashed circle ⦸ means the burner is out of air. However, the burner may operate unsafely long before reaching this point. See Sample Problems at bottom for examples.  
   
   
   
  H/C ratio of fuel    Oxygen Excess Air   Ratios    
  Air Temp. at Known O2 F Known O2 %          
  Minimum Air Temperature F O2 at Minimum Air Temp. % Fuel Factor    
  Maximum Air Temperature F O2 at Maximum Air Temp. %          
                                       
    H/C Ratio for Some      
    Common Fuels   New Air Temp. [°F] Air Temperature at Known O2 [°F]    
    Fuel H/C   30 40 50 60 70 80 90 100 110 120    
    Natural Gas 3.80   30    
    Propane   40    
    Fuel Oils   50    
            60    
            70    
            80    
            90    
            100    
            110    
            120    
                                       
  Sample Problem 1 (Performance): If a natural gas burner runs at 3% O2 with 60°F air, to what will be the O2 with 90°F air? (Sample inputs and Results shown directly below.)  
   
  H/C ratio in the fuel (see table) 3.80   Oxygen Excess Air   Ratios    
  Air Temp. at Known O2 60 F Known O2 3.0 % 8.7% ρnew/ρknown  0.945    
  New Air Temp. 90 F O2 at New Air Temp. 1.9 % 15.0% Fuel Factor 0.898    
  Answer: The O2 will fall to 1.9%. Note: O2 levels of ≤2% may be unsafe and some burners may require >2% O2.  
  Sample Problem 2 (Set up): What O2 is required for a natural gas burner running with 60 °F air in order to deliver 3% O2 at 110°F? (Sample inputs and results shown directly below).  
   
  H/C ratio in the fuel (see table) 3.80   Oxygen Excess Air   Ratios    
  Air Temp. at Known O2 110 F Known O2 3.0 % 26.0% ρnew/ρknown  1.096    
  New Air Temp. 60 F O2 at New Air Temp. 4.7 % 15.0% Fuel Factor 0.898    
  Answer: The O2 should read 4.7% at 60°F in order to achieve 3.0 % at 110°F for a given burner setting.  
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         1000 East Bald Eagle Street, Lock Haven, PA 17745-3215  
          Phone: 570-748-4009, Fax: 570-748-4324, Email: sales@faberburner.com