Hot Water Boiler - Water Circulation Rates

           

   Boiler power and water flow through boilers - Imperial and SI-units

    The relation between

•  Boiler capacity (or power)
•  Temperature drop of the water flow in a system serviced by boiler
•  Circulated water flow

               are indicated in the diagrams below:

Water Circulation - Boiler Capacity in BHP - Temperature drop in degrees Fahrenheit

• 1 gal (US)/min = 6.30888x10^-5 m³/s = 0.0227 m³/h = 0.06309 dm³(liter)/s = 2.228x10^-3 ft³/s = 0.1337 ft³/min = 0.8327 Imperial gal (UK)/min
• 1 hp (English horse power) = 745.7 W = 0.746 kW = 550 ft lb/s = 2,545 Btu/h

      Water Circulation - Boiler Capacity in MBtu/h - Temperature drop in degrees Fahrenheit

       

• 1 Btu/h = 0.293 W

                 Water Circulation - Boiler Capacity in kW - Temperature drop in degrees Celsius

• 1 kW = 3,412 Btu/h = 1.341 British hp

Example - Water flow through Boiler

A boiler with capacity 50 kW increases the temperature of the circulated water with 20^oC - the water flow through the boiler according the diagram above is 0.6 kg/s