Hot Water Recirculation Design

Calculate recirc system requirements

Piping Details

Include supply and return (if dedicated)

Temperature Settings

Recirculation Results

Required Flow Rate --
Heat Loss --
Pump Size --
Return Line Size --
Annual Energy Cost --

System Comparison

System Pros Cons
Dedicated Return Most efficient, instant hot water Requires return piping
Demand System Energy efficient, retrofit Short wait time
Crossover No return pipe needed Cold water warm-up

Design Considerations

Pump Selection

  • Bronze or stainless pump
  • 1/25 to 1/6 HP typical
  • Timer or aquastat control
  • ECM pumps save energy

Energy Saving Tips

  • Timer during occupied hours
  • Aquastat with deadband
  • Demand pump activation
  • Proper pipe insulation

Code Requirements

  • Check valve at return
  • Balancing valves per branch
  • Insulation per energy code
  • Thermal expansion tank