How Can the Combustion System Be Improved?

Flue gases are the single most important cause of energy loss. As much as 18 to 22 percent of available energy goes up the chimney. Heat radiation and convection from boiler walls raise heat loss another 1 to 4 percent.

There are four main ways of reducing flue gas energy losses:

* by improving the efficiency of converting the fuel to heat (improved combustion system efficiency)
* by requiring less air for satisfactory combustion
* by ensuring that the boiler casing is tight, so that there is no air/heat entering or leaving the casing through leaks
* by improving the efficiency of transferring the heat to the steam or hot water (improved heat exchanger efficiency)

Operating practices such as blowdown cause other losses, as do inefficiencies in steam and hot water distribution systems.