The Tool Box.Free calculators for commissioning engineers.
Duct, pipe, louvre, tank, coil, hydronic and efficiency sizers our engineers use during design reviews, witnessing and audits. No sign-up, no paywall — built by commissioning engineers, for commissioning engineers.
Deep-dive engineering calculators
Individually documented calculators with worked examples — one page each, shareable, indexable, cite-able in reports.
Reconcile flow, ΔT and coil duty — detect low ΔT syndrome fast.
Darcy-Weisbach head loss + indicative pump shaft power.
Supply airflow, coil face area and duct velocity from cooling load.
Indicative commissioning programme days from GFA + complexity.
Indicative NABERS Energy band from EUI for offices.
Quick sizers for design verification
Twelve building-services calculators for ducts, pipes, louvres, tanks, coils, hydronic valves, fan & pump affinity, COP, ROI and tolerance audits — the modules our engineers reach for during design reviews and site witnessing.
Configuration Inputs
Sizing Selections & Outputs
Calculated values are aligned with standard temperature air/water densities under CIBSE and ASHRAE commissioning frameworks to provide realistic engineering baselines.
Air Distribution Audits
Commissioners audit ductwork systems to verify structural integrity, perform duct leakage testing (Duct Leakage Class), and verify that static pressure drops do not exceed fan design limits.
Field commissioning calculator desk
DW/143 duct leakage, pitot traverse airflow and CIBSE Code W water flow — the three field calculators commissioning engineers use to verify measured results against design intent on the day.
Field Commissioning Calculators
Test Setup Parameters
Measured Site Leakage
0.326 L/s/m²
Compliance Verdict
Applying on-site sizing & commissioning practice:
Always verify that calibration parameters match the specific manufacturer's valves on site before recording final dynamic flow readings.
Estimated heat load sizer
A first-pass W/m² envelope for cooling and heating loads used in pre-design reviews — to challenge over-specified plant capacity before procurement is locked in.
Estimated Heat Load Sizer
Sizing Inputs
Estimated Thermal Capacity
Sizing Validation
PCM uses these indexes as verification envelopes during design review. If specified plant exceeds these values by more than 20%, we flag potential over-sizing.
100 W/m²
Applying Early-Stage Commissioning Sizing Practices
Verifying raw heat load parameters during pre-design review ensures mechanical plants are not over-specified — saving significant capital expenditure and downstream commissioning energy.
mc ΔT energy auditor
Reconcile measured flow and temperature difference against rated coil duty — the fastest way to detect low ΔT syndrome, valve authority issues and fouled heat exchangers on site.
mc ΔT Energy Auditor
Energy Calculations
Result Panel
Governing Equation
Energy balance verification — used during witnessing to reconcile measured coil duty against design intent.
Applying On-Site Energy Reconciliation
Reconciling measured flow + ΔT against rated coil duty is the fastest way to detect low ΔT syndrome, control-valve hunting and fouled heat exchangers before they cascade into plant inefficiency.
Take the full commissioning portal for a spin.
The calculators are the free layer. The portal is where PCM tracks the whole handover — assets, ITPs, defects, Soft Landings. Open a live demo project with one click.
- Anonymous — no sign-up
- Seeded demo project
- Every module unlocked
One click. Full portal.
Launches an anonymous session scoped to the seeded demo project. Nothing to install, nothing to sign.