Hot Water Boiler - Circulation Rates

Calculate boiler power and water flow relationships in imperial and SI units. Determine circulated water flow based on boiler capacity and temperature drop.

Hot Water Boiler - Circulation Rates

Boiler power and water flow - 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.

Calculator

Inputs

Results

Water Flow Rate-- kg/s
Water Flow Rate-- gal/min (US)
Water Flow Rate-- gal/min (US)

Conversion Factors

Flow Rate Conversions:

  • 1 gal (US)/min = 6.30888×10⁻⁵ m³/s = 0.0227 m³/h = 0.06309 dm³(liter)/s = 2.228×10⁻³ ft³/s = 0.1337 ft³/min = 0.8327 Imperial gal (UK)/min

Power Conversions:

  • 1 hp (English horse power) = 745.7 W = 0.746 kW = 550 ft lb/s = 2,545 Btu/h
  • 1 Btu/h = 0.293 W
  • 1 kW = 3,412 Btu/h = 1.341 British hp

Example

A boiler with capacity 50 kW increases the temperature of the circulated water by 20 °C - the water flow through the boiler is 0.6 kg/s

Hot Water Boiler - Circulation Rates | MEPKit Engineering Tools | MEPKit