HVAC Hydronic Pipe Calculator

HVAC Hydronic Pipe Sizing Calculator is the professional tool for HVAC technicians, plumbers, and hydronic system installers. Calculate correct hydronic pipe size based on flow rate (GPM) with automatic velocity and pressure drop calculations — using Darcy-Weisbach hydraulic analysis for accurate heating and cooling system design. PIPE MATERIAL TYPES: Copper Type L — Standard copper tubing for residential systems Copper Type M — Thinner copper for high-pressure applications Steel Schedule 40 — Carbon steel pipe for industrial systems CPVC — CTS SDR-11 per ASTM D2846, 1/2" to 2" hot/cold water sizes PEX — Cross-linked polyethylene for modern systems CORE SIZING FEATURES: Flow Rate Sizing — Enter GPM to get recommended standard pipe sizes instantly Velocity Check — Ensures flow stays within safe limits (optimal 3-10 FPS) Pressure Drop Analysis — Darcy-Weisbach calculation per 100 ft of pipe Reynolds Number — Full hydraulic analysis for precision system design Standard Sizing — All results snap to industry-standard nominal pipe sizes Instant Results — Calculated velocity and friction loss displayed immediately FLUID SUPPORT: Water Only — Standard hydronic heating water calculations 30% Glycol Mixture — Anti-freeze protection for cold climates 50% Glycol Mixture — Maximum freeze protection systems Automatic Density/Viscosity — Adjusts calculations for fluid type ADVANCED CALCULATIONS: Pressure Drop Per 100 ft — Complete friction loss analysis Velocity Verification — Confirms proper flow rates prevent erosion Glycol Property Presets — Density and viscosity adjust automatically Limit Warning — Flags results that exceed velocity or pressure-drop limits Friction Factor Display — Swamee-Jain (Colebrook) factor on every result OPTIONAL PRO UPGRADE — $2.99 ONE-TIME IN-APP PURCHASE The following features require a separate one-time in-app purchase. They are not required to use the calculator: • Unlimited saved calculation history • PDF export of results • Dark theme • Ad-free experience WHY HYDRONIC & HVAC PROS USE THIS APP: Faster pipe sizing than friction loss charts and tables Accurate sizing prevents undersized/oversized pipes Reduces pressure drop problems in hydronic systems Ensures proper flow velocities for system efficiency Prevents erosion damage in copper piping (>10 FPS) Prevents noise and cavitation in hydronic systems PERFECT FOR: HVAC technicians designing hydronic heating systems Plumbers sizing water and glycol piping Hydronic system installers planning equipment layouts HVAC contractors preparing accurate material estimates Geothermal heat pump system designers Radiant floor heating system design HVAC students learning hydronic calculations Building commissioning engineers Based on Darcy-Weisbach friction loss methodology and industry-standard hydraulic calculations. Part of HVACTools Suite — professional HVAC technician tools for hydronic design, refrigeration diagnostics, and field calculations.