HVAC ENGINEERING TOOL

Chilled Water Flow Calculator

Calculate water flow from cooling capacity and either CHW temperatures or direct ΔT.

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Formula / Method

V̇ = Q ÷ (ρ × Cp × ΔT); ΔT = return − supply

Engineering Method & Assumptions

Water only; density 1,000 kg/m³.
Cp = 4.186 kJ/(kg·K).
No glycol, pump heat, pipe-loss or fouling correction.

Applicability: This fixed-property design approximation is not a temperature-dependent fluid-property model.

WHEN TO USE THIS TOOL

Useful during hydronics & capacity work.

Convert cooling duty into the flow or capacity units used by different teams and equipment schedules.
Perform early-stage hydronic checks before detailed pump, pipe or equipment selection.
Cross-check design assumptions such as ΔT, internal diameter and operating flow before issue.

Frequently asked questions

How is chilled-water flow calculated?

Cooling capacity is divided by water density, specific heat and the positive water temperature difference.

Why does ΔT affect required flow?

For the same capacity, a larger ΔT carries more heat per unit mass and therefore requires less flow.

Does this calculator support glycol?

No. Phase 1 is for water only and applies no glycol correction.