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Heating Pipe Size Calculator
Calculate the correct pipe diameter for heating and chilled water systems based on flow rate and maximum velocity. Get the recommended standard copper pipe size.
How to Size Heating Pipes
Pipe sizing balances flow rate against velocity. Too high a velocity causes noise and erosion; too low a velocity means oversized, expensive pipes.
For heating systems, a maximum velocity of 1.0 m/s is typical for small pipes and 1.5 m/s for larger pipes. Chilled water systems may allow up to 2.0 m/s.
Frequently Asked Questions
What velocity should I use for heating pipes?
0.5–1.0 m/s for pipes up to 25 mm, 1.0–1.5 m/s for 25–50 mm pipes, and 1.5–2.0 m/s for larger pipes. Keep noise within acceptable limits.
What are standard copper pipe sizes in the UK?
Common UK copper tube sizes (OD): 15 mm, 22 mm, 28 mm, 35 mm, 42 mm, 54 mm, 67 mm, 76 mm. Smaller sizes are used for branch circuits, larger for mains.
Heating Pipe Size Calculator
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