{
 "schema": "spawner-tool/v1",
 "id": "bot_018",
 "name": "U‑Wert Berechnung – Dämmung schnell ermitteln",
 "description": "Berechnen Sie den U‑Wert Ihrer Dämmung mit wenigen Eingaben.",
 "url": "https://fachrechner.com/de/daemmung-u-wert-berechnen/",
 "spec_url": "https://fachrechner.com/de/daemmung-u-wert-berechnen/spec.json",
 "language": "de",
 "market": "DE",
 "live_since": "2026-10-25T16:18:37Z",
 "inputs": [
  {
   "id": "lambda_w_mk",
   "label": "Wärmeleitfähigkeit des Materials",
   "unit": "W/(m·K)",
   "min": 0.01,
   "max": 1.0,
   "step": 0.001,
   "default": 0.04
  },
  {
   "id": "thickness_m",
   "label": "Dämmstoffdicke",
   "unit": "m",
   "min": 0.01,
   "max": 0.5,
   "step": 0.01,
   "default": 0.2
  }
 ],
 "constants": [
  {
   "id": "r_si",
   "value": 0.13,
   "source": "Standardinnenflächenwiderstand (DIN 4108)"
  },
  {
   "id": "r_se",
   "value": 0.04,
   "source": "Standardaußenflächenwiderstand (DIN 4108)"
  }
 ],
 "outputs": [
  {
   "id": "u_wert_w_m2k",
   "label": "U‑Wert",
   "unit": "W/(m²·K)",
   "decimals": 3,
   "expression": "1/(thickness_m/lambda_w_mk + r_si + r_se)"
  }
 ],
 "formula": "U‑Wert = 1 ÷ (R_si + d/λ + R_se)",
 "expression_language": {
  "name": "safeexpr",
  "syntax": "Python arithmetic subset: + - * / ** %, parentheses, numbers, input/constant ids and ids of earlier outputs, functions abs sqrt log log10 exp floor ceil sin cos tan min max round(x,n), constants pi e, conditionals (a if x > y else b)",
  "semantics": "% is fmod; round() rounds half away from zero; outputs are evaluated in the listed order"
 },
 "example": {
  "inputs": {
   "lambda_w_mk": 0.04,
   "thickness_m": 0.2
  },
  "outputs": {
   "u_wert_w_m2k": 0.193
  }
 },
 "verification": "formula checked against independent test vectors; browser JS equals the reference evaluator",
 "commercial_action": null,
 "api": {
  "endpoint": "https://fachrechner.com/api/v1/calc/bot_018",
  "method": "GET",
  "parameters": "input ids as query parameters (missing = default); response JSON with outputs",
  "free_calls_per_day": 10,
  "auth": null,
  "on_limit": "HTTP 402 daily_limit_reached (no paid tier; quota resets 00:00 UTC, Retry-After)",
  "pro_checkout": null,
  "expression_tree": "https://fachrechner.com/m2m/bot_018.json"
 }
}