What is the BTU/hr equivalent of one boiler horsepower?

One boiler horsepower is defined as the ability to produce steam at a rate of 34.5 pounds of steam per hour from water at a temperature of 212 degrees Fahrenheit. To convert this to BTUs, it's important to recognize that it takes 970.3 BTUs to evaporate one pound of water at that temperature. By multiplying the 34.5 pounds of steam per hour by the 970.3 BTUs needed for each pound, the total comes to approximately 33,475 BTU/hr.

This conversion is essential in steamfitting, as it allows professionals to determine the thermal output of boilers relative to the BTU/hr measurement, which is commonly used in heating calculations. This understanding is crucial for sizing boilers, calculating efficiencies, and ensuring that heating systems function effectively in various applications.