For Electric Customers
In many installations, steam and water boilers are manufactured with only a main natural gas burner. This burner can only be shut on and off and is designed for large amounts of natural gas when steam or water demand is high. A modulating burner is a smaller burner used along with a main burner to increase energy efficiency.
When demand is low, the main burner is cycled on and off and requires large amounts of fuel and adds many operational steps to protect the equipment from being over heated and damaged. A smaller modulating burner can be used to work along with the main burner. When demand is low, the smaller modulating burner may take the place in operation using less natural gas, while meeting the steam or water needs.
Modulating burners are also a great addition during the startup of a boiler. A boiler that has been off for a period of time needs to be warmed up at a certain rate to allow for thermal growth. The larger main burner again has to be shut on and off to keep the heating of the equipment at a very slow rate. The use of a modulating burner, much smaller than the main burner, can be started and gently allow all the equipment to warm up at manufacturer specification protecting the equipment from being overheated.
If the heat source can be made to modulate, there can be considerable savings in natural gas due to combustion processes. Pressure/temperature output can remain more constant which may be of benefit. If combustion gas temperature falls too low in the boiler/heater, condensation may occur. If the boiler is not designed to resist the corrosive effect of this, serious problems could occur.