Free Engineering Tools

12 calculators and templates for people who run heating networks, water systems, HVAC plants and industrial equipment. Built by an engineer who does that job every day. They are free, need no sign-up and run entirely in your browser, so nothing you type leaves your computer.

Heating, water & HVAC

Hydraulic and thermal calculations for heating networks, boiler houses, water supply and air conditioning: from heat load to flow, pipe size, pressure drop, pump energy, insulation and condensation.

HeatingHeating Flow Rate CalculatorHeat load to flow rate and back (Q = m·cp·ΔT) for heating and chilled water: kW, BTU/h, Gcal/h, m³/h, GPM, water and glycol.Open the tool →HydraulicsPipe Size CalculatorPick the smallest standard steel, PE or copper pipe that meets your velocity and pressure drop limits for a given flow.Open the tool →HydraulicsPipe Pressure Drop CalculatorVelocity, Reynolds number, friction factor and pressure loss in water pipes, with temperature-corrected water properties.Open the tool →PumpsPump Power & Energy Cost CalculatorHydraulic, shaft and electrical power, yearly energy and cost, and what a variable speed drive could save over throttling.Open the tool →InsulationPipe Heat Loss CalculatorHeat loss per metre for bare and insulated pipes, surface temperature, yearly energy and cost by insulation thickness.Open the tool →HeatingExpansion Tank CalculatorExpansion vessel size, pre-charge and fill pressure for closed heating systems, using the EN 12828 method.Open the tool →HVACDew Point & Condensation CalculatorDew point, humidity ratio and wet bulb from temperature and RH, and whether a cold pipe or duct will sweat.Open the tool →

Maintenance & reliability

Numbers that turn maintenance arguments into budget decisions: what downtime costs, which spares to stock, how reliable the equipment really is, and how to prepare an outage.

MaintenanceCritical Spare Parts CalculatorHow many spares to keep on the shelf: holding cost compared with the cost of downtime while you wait for delivery.Open the tool →MaintenanceDowntime Cost CalculatorThe real cost of one hour, one breakdown and a year of unplanned downtime, and where the money goes.Open the tool →ReliabilityMTBF, MTTR & Availability CalculatorMean time between failures, mean time to repair, availability and the chance of a month without a breakdown.Open the tool →PlanningShutdown Readiness ChecklistPrintable checklist for planned outages: what must be ready 24 hours before, control during the work, and the debrief.Open the tool →RecordsEquipment Log Template for Google SheetsReadings log and failure log for pumps, boilers, chillers and more, ready to paste into Google Sheets or download as CSV.Open the tool →

How the tools fit together

Several of the calculators hand their results to each other. Start with the heat load in the heating flow rate calculator, pick a pipe for that flow in the pipe size calculator, check the whole run in the pressure drop calculator, and see what moving the water costs with the pump energy calculator. The results carry over through the links, so you do not have to retype them.

On the maintenance side, the equipment log template gives you the records, the MTBF calculator and the downtime cost calculator turn them into numbers, and the spare parts calculator turns those into a stocking decision.

A note on accuracy

Every tool explains its formulas and assumptions on its own page. They use standard engineering methods and are meant for quick checks, preliminary sizing and budget arguments. For final design of safety-critical systems, follow your local codes and manufacturers' data. If you find an error, please tell us at support@ceoneuro.com.

Have the numbers in a spreadsheet already?

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