thermoNavi Retrofit Efficiency

Frequently asked questions

What kinds of buildings can I use thermoNavi for? +
Existing buildings Simplified method SFH / TFH / MFH

thermoNavi is built as an end-to-end workflow for existing buildings, especially single- and two-family houses and smaller multi-family buildings with typical radiator systems.

  • Existing-building focus: new builds face different legal requirements with full normative procedures.
  • Standards: DIN EN 12831 together with DIN/TS 12831-1 allow a simplified method for existing buildings.
  • Optimised for solid precision with straightforward data entry.
  • Individual features (radiator optimisation, hydraulic balancing) can in principle also be used in new builds; the overall product is developed for the existing building stock.
Why is thermoNavi free? +
Free permanently System flow temp Pro optional

A well-designed heat pump is one of the strongest levers for efficient heating. Many systems underperform, often because flow temperatures are too high.

  • Common causes: mismatched heat loads, emitters, or missing hydraulic balancing.
  • thermoNavi looks at emitters across rooms, finds critical rooms, and aims for the lowest practical system flow temperature.
  • Even small design improvements add up across many installations.
  • Core functionality stays free permanently, including without an account.
  • The Pro plan optionally adds multi-project management, site photos and company branding for trade businesses (see Plans).
Do I need an account to use thermoNavi? +
No account needed 1 project Cloud with account

No. You can use thermoNavi immediately without registering, as a homeowner or as a trade professional.

  • Free: one project from inputs through optimisation to a PDF report, at no charge. Without an account it stays in this browser; with a free account it syncs in the cloud across devices.
  • Pro: extended project management, site photos and company branding for trade professionals (for example a phone on site and a PC in the office).
What happens to my data? +
Local without account No tracking EU cloud with account

Your inputs belong to you. Without an account, projects stay in this browser. With an account they are stored in the cloud in the EU.

  • No analytics tracking and no analytics cookies in the app.
  • Without an account: data does not leave your device except when you export (e.g. PDF) or save on the device yourself.
  • With an account: project data is stored in our provider’s cloud in the EU. Photos and logos only with Pro.