Michaels Energy

A vast majority of boilers, regardless of age, test 80% or better on combustion efficiency! Even some ancient coal boilers that were converted to gas decades ago are typically in the 80% efficiency range.

A rule of thumb is that for every 40F decrease in boiler stack temperature, there is an increase in boiler efficiency of 1%! While this may not sound like a lot, it can translate to big savings and short paybacks.

Many boiler plants are doing just that, continuously dumping hot water down the drain for boiler blowdown. In addition, cold water is often added to the hot blowdown water to meet sewer temperature requirements.