Chilled & Condenser Water Pipe Sizing

Enter your cooling load and chiller plant data to get the chilled-water and condenser-water flows and the recommended Schedule-40 pipe and header sizes — selected to ASHRAE / SNI velocity and friction limits. Related: see the chiller plant in 3D.

Enter the design flow straight off your equipment schedule. The header carries the total flow, each branch carries one unit, and a pump branch carries the total shared across the duty pumps.

Chilled water — evaporator side

Flow per chiller (GPM) Chiller evaporator design flow, per unit.

Number of chillers

CHW pumps — duty (running) Pumps sharing the flow; exclude standby.

Condenser water — cooling-tower side

Flow per cooling tower (GPM) Tower / chiller-condenser design flow, per unit.

Number of cooling towers

Condenser pumps — duty (running) Pumps sharing the flow; exclude standby.

Advanced limits

Max velocity (m/s)

Max friction (Pa/m)

Hazen-Williams C140 steel/PVC, 130 copper.

Total chilled-water flow

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Total condenser-water flow

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Segment	Flow	Pipe size	Velocity	Friction

How it sizes: each segment's pipe is the smallest Schedule-40 size whose velocity ≤ the limit and friction ≤ the limit (Hazen-Williams). Branch = one unit's flow, header = all units combined, pump branch = total ÷ duty pumps. Indicative only — confirm against full pump head, fittings and the equipment selected. Need it built? Talk to our engineering team.

Total cooling load

Number of chillers The header carries the total flow; each branch carries one chiller.

Chilled water ΔT (°C) Typical 5–6 °C (e.g. 12.5 → 7 °C).

Condenser water ΔT (°C) Typical ~5 °C (32 → 37 °C).

Chiller COP Sets condenser heat rejection = load × (1 + 1/COP).

Advanced limits

Max velocity (m/s)

Max friction (Pa/m)

Hazen-Williams C140 steel/PVC, 130 copper.

Plant load

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Chilled water flow

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Condenser water flow

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Pipe	Flow	Size	Velocity	Friction

Method: water flow = load ÷ (4.187 × ΔT). Pipe size is the smallest Schedule-40 DN whose velocity ≤ the limit and friction ≤ the limit (Hazen-Williams). Defaults follow ASHRAE / SNI 6390 practice — ≤1.2 m/s for small pipes, ≤400 Pa/m friction. Indicative only — confirm against a full hydraulic design, fittings, pump head and the equipment selected. Need it sized and built? Talk to our engineering team.

From Sizing to Installation

We don't just size the pipes — we engineer, fabricate, install and commission the complete chiller plant.