ABSTRACT
Both Heat Loss and Input-Output boiler efficiency calculations are included in the American Society of Mechanical Engineers short Form. This power test code has become the standard test procedure in many countries. It neglects minor efficiency losses and heat credits, considering only the Higher Heating Value of the input fuel. The Input-Output test method is also very labor intensive. Precision instrumentation must be specified and installed. Test runs are usually more than four hours and must be rejected for any inconsistent data. Trial runs are often required to check out instrumentation and identify problems with the boiler as well as to train test personnel and observers. The heat loss method is a much more accurate and more accepted method of determining boiler efficiencies in the field provided that the measurements of the flue gas conditions are accurate and not subject to air dilution or flue gas flow stratification or pocketing.
