Steam Heating > Boiler Combustion Controls

Existing Conditions

Two gas fired, firebox style boilers provide steam perimeter heating to the original school. The steam plant also supplies a steam coil in the main air handling unit AHU1 and four steam to hot water converters. Two of these steam converters supply perimeter heating for the additions and the other two supply domestic hot water.

The boilers are in relatively good shape, given their age. The combustion air damper on one of the burners has been disconnected from the linkage and set in one position. Therefore, combustion air control is poor.

The building operators have indicated that only one boiler is required, even on the coldest days.

Retrofit Conditions

We recommended the installation of a boiler combustion control system on each boiler. The system must be capable of adjusting combustion air based on feedback of the combustion products. The amount of excess air can typically be reduced to below 5%, increasing the efficiency of the boiler plant.

We recommend a Fireye Focus Combustion Efficiency System because:

•	It is less expensive than most combustion efficiency systems.

•	It constantly monitors and adjusts the fuel/air ratio.

•	It optically monitors the combustion products at the flame instead of monitoring at the stack. This is a more reliable method.

We have recommended a system for each boiler. It may be possible to reduce costs while maintaining almost all savings by only installing the system on one boiler. If this is done, it is important to make sure that the second boiler is not used, and that the combustion air damper and linkage on the burner is repaired and set up properly.

This recommendation is in accordance with Measure HV1 of the CMHC manual on Energy and Water Efficiency in Multi-Unit Residential Buildings.1

Further Benefits

Application Details

Available with a wide range of features and prices. Economical for larger boilers. Not worth the additional maintenance and failure potential in smaller boilers that are not as closely supervised.

Issues and Concerns

References

1 The CMHC manual on Energy and Water Efficiency in Multi-Unit Residential Buildings can be found online at www.hwbinc.com/495-1003/introduction.html.

Analysis

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