Engineering Tools

Size Your System in Minutes

Free, SANS-based sizing tools built by SIRAC engineers. Get an indicative system selection on screen, then send your spec straight to our team for a fully engineered design.

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Heat Pump Sizing Calculator

Size a SIRAC heat pump system to SANS hot water allowances, then match it to Thermocube or Thermotube storage. Includes COP de-rating for cold climates and a printable spec sheet.

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Coil Sizing Calculator

Size the stainless-steel heat-exchanger coils for a Thermocube or Thermotube vessel from your flow rate and water temperatures. Reads the heat exchange coefficient and pressure drop off the SIRAC tubing curve at your actual flow.

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Coming Soon

SANS 10400-XA Compliance Checker

See how a SIRAC heat pump system contributes to a building’s energy-efficiency compliance under SANS 10400-XA, with an indicative note for your plans submission.

Results from these tools are indicative and intended for early-stage planning. Final system design, model selection and performance should always be confirmed by the SIRAC engineering team.

Sizing tools for commercial hot water systems

These are the same calculations SIRAC engineers use when scoping a project, published so consulting engineers, contractors and developers can get to an indicative answer without waiting on a call. Both tools are free, need no login, and produce a printable technical specification you can attach to a tender or a budget submission.

Heat Pump Sizing Calculator

Works out how much hot water storage a building needs from the SANS 10252 storage allowance for its occupancy type, converts that into a heating load over your chosen recovery period, adds line losses, and matches the result to a SIRAC heat pump selection. It will also size the storage vessel and its heat-exchanger coil kit. Open the heat pump sizing calculator.

Coil Sizing Calculator

Works out the coil length, coil count and pressure drop for the heat exchanger inside a hot water storage vessel, from your flow rate and water temperatures. Heat exchange coefficient and pressure drop are read off the SIRAC tubing curve at your actual per-coil flow rather than assumed. Open the coil sizing calculator.

What these tools are, and are not

They give a defensible indicative selection for early-stage planning, budgeting and tender scoping. They are not a substitute for an engineered design: final model selection, redundancy, pipework, controls and commissioning are confirmed by the SIRAC engineering team against the specific project. Every result can be sent straight to that team for review at no cost.

Who uses them

Typical applications include hotels, hospitals and clinics, high-rise residential, student accommodation, social housing and commercial buildings.