Hydronic Flow GPM Calculator
Who it's for: Hydronic HVAC technicians, estimators, and service teams.
Calculator Inputs
Quick Summary
- Built for: Hydronic HVAC technicians, estimators, and service teams.
- Key outputs: Estimated flow (GPM), Heat load and Delta T used, and more.
- Use this page for early planning estimates before final code and manufacturer verification.
Inputs
- Heat load (BTU/hr)
- Delta T (F)
- Glycol percent (informational)
Outputs
- Estimated flow (GPM)
- Heat load and Delta T used
- Constant/assumption note
How this calculator estimates results
- Uses the common hydronic estimate equation: GPM = BTU/hr / (500 x dT).
- Calculates flow directly from entered heat load and delta-T values.
- Displays glycol as informational input without changing the constant in this MVP.
Cross-check assumptions with Baseboard Heater Size Calculator for a more complete planning workflow.
Common ranges and tips
- Choose Delta T based on your design intent and emitter/system strategy.
- For glycol systems, verify final flow with corrected fluid properties.
- Use this as a planning estimate and confirm with full hydronic design checks.
Related Calculators
FAQ
It is a common water-system approximation combining water density and specific heat in HVAC units.
Yes in real systems, but this MVP keeps 500 fixed and reports glycol only as an informational note.
Use your project/design target Delta T; different system strategies may use different values.
No. Use this for planning and verify final sizing with full design methods and equipment data.
Disclaimer: Use results for planning only. Final design and installation decisions must follow local code and manufacturer documentation.
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