How many pounds of water must be evaporated per hour to equal one boiler horsepower?

One boiler horsepower is defined as the ability to convert water into steam at the rate of 34.5 pounds of water per hour. This measurement is based on the understanding that one boiler horsepower can produce steam at a pressure of 0 psig, which translates to the energy required to turn water into steam under standard conditions.

This figure is used as a standard in the industry for calculating the capacity of steam boilers and helps in determining the energy efficiency of heating systems. Therefore, 34.5 pounds becomes a critical conversion metric in many calculations related to heating, boiler sizing, and overall energy management in building maintenance practices. The correct choice reflects not only the standard industry definition but also enables facility managers to accurately assess their boiler systems and their performance metrics in relation to energy output and water usage.