Temper-3D is a finite element solver for thermal bridges and window frames that lives in the browser. Open the model and results in a tab with nothing to install, ask the built-in AI assistant to explain or change the model, or let Claude, Cursor and other agents run calculations through our MCP server. REST API for everything else. Accuracy is checked against the EN ISO 10211 and 10077-2 benchmark cases.
Free tier: up to 2,000 mesh nodes and 1 minute of compute per day, sign-in by email code (the sign-in page is in Russian).
Add the server once, then ask your assistant to calculate a junction. It estimates the size, submits the model, waits for the result and reads the flows back to you.
temper_estimatetemper_submittemper_wait_runtemper_get_resulttemper_get_runtemper_list_runstemper_canceltemper_convert_to_frstemper_me
Claude Code, a custom connector in Claude.ai and Claude Desktop, Cursor and VS Code: any MCP client that supports remote HTTP servers with OAuth.
# MCP: add the server to Claude Code, then sign in with /mcp
claude mcp add --transport http temper https://api.temper3d.ru/mcp
# REST: estimate without spending quota, then submit
curl -H "Authorization: Bearer $TOKEN" \
-X POST https://api.temper3d.ru/v1/estimates -F frs=@model.frs
curl -H "Authorization: Bearer $TOKEN" -H "Idempotency-Key: my-case-1" \
-X POST https://api.temper3d.ru/v1/submissions -F frs=@model.frsFour kinds of users with the same problem: a hand calculation stops working at the junction, and the result has to survive review.
Problem. Catalogues of psi values do not cover your detail, and a reviewer asks how the number was obtained.
With Temper-3D. Heat flow balance, the EN ISO 10211 mesh checks and the minimum surface temperature are in every result. A result opens from a short link, so a reviewer can open it and recalculate.
Problem. Every profile and every installation detail needs its own U_f, psi and condensation check.
With Temper-3D. Frame calculations to EN ISO 10077-2, installation junctions in 3D, serial runs through the API, a parametric junction template.
Problem. Desktop solvers have no programmable interface, so they cannot sit inside a BIM pipeline or an AI workflow.
With Temper-3D. REST API, MCP server and a plain-text model format that a script or a language model can write, diff and fix.
Problem. Students need real junctions, not an installer and a licence server.
With Temper-3D. The four EN ISO 10211 test cases and the EN ISO 10077-2 frame case are solved and open for checking. The solver runs in a browser tab.
Temperature field and heat flow through any junction: corners, balcony slabs, fasteners, window reveals.
Psi (linear, W/(m·K)) and chi (point, W/K) from the flow through the junction. Fasteners, for example, are a chi calculation.
Surface temperature against dew point, and the temperature factor f_Rsi at every point of the inner surface.
Two-dimensional conductance L2D and frame transmittance U_f under EN ISO 10077-2.
We state exactly what was checked: the benchmark cases of the standards. This is not a third-party certificate of conformity to EN ISO.
Dimensions in millimetres, conductivity of materials, air temperatures. The model is a short text container (.frs) that you can read, diff and edit.
Estimate the node count first, then submit. The solver checks the EN ISO 10211 conditions on a refined mesh.
Temperature field, flows through every surface, minimum surface temperature and heat balance. Share the result by a short link.
Example from our tutorial: with +20 °C inside and -23 °C outside, the inner surface of a wall is at 18.70 °C, a flat corner at 16.76 °C and a corner at the ceiling at 13.64 °C. A one-dimensional formula sees only the first number. Tutorial, corners (in Russian)
THERM, Flixo and HEAT2/HEAT3 are mature desktop tools. We compare on the three points where we differ, and only on what we could verify.
 Temper-3D | THERM, Flixo, HEAT2/HEAT3 | |
|---|---|---|
| Browser or installation | ✓Runs in a browser tab: model, calculation and results | ✗Desktop programs you install and license |
| AI | ✓Built-in assistant that edits the model and explains results | ✗No AI features found on their sites (November 2026) |
| MCP and API | ✓MCP server and REST API | ✗No MCP server found for any of them (November 2026) |
If a desktop program fits your work, use it. If you want the calculation in a browser, in an agent or in a pipeline, this is the difference.
Simple calculations are free. Larger ones are priced by size and volume.
Up to 2,000 mesh nodes and 1 minute of compute per day. Flat junctions, learning, checking a method. Sign-in by email code.
Start freeModels up to 80,000 nodes with higher daily limits, for offices and organisations. Invoice and contract.
Ask for a quoteUp to 3 million nodes, API volume, education and integration terms on request.
Talk to usTell us about your junction and what you need to prove with it. We reply by email.