Hydronic Loop Sizing Calculator (Radiant Heat)
Why keep water velocity under 4 ft/s?
Sustained velocity above roughly 4 ft/s causes flow noise, accelerates erosion-corrosion of pipe walls, and raises pumping head unnecessarily. ASHRAE pipe-sizing guidance and standard residential practice cap velocity at about 4 ft/s, which is the threshold this tool enforces when recommending a size.
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Use the Hydronic Loop Sizing Calculator (Radiant Heat) to get an exact answer for your inputs.
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