happytails.ai

Insulation payback calculator

Open Insulation payback calculator on Happytails.ai. This view has the same page content and links, with explicit tool capabilities. Read the processing notes before using a tool.

Tool capabilities

{
  "id": "insulation-payback-calculator",
  "category": "calculators",
  "built": true,
  "requirements": "Element area above 0 to 1,000,000 m², U-values 0 to 20 W/m² K, heating degree days 0 to 20,000 K days, heating efficiency or COP above 0 to 20, price per input kWh 0 to 100,000 and installed cost 0 to 1 trillion in one currency. Area accepts m² or ft². Calculated on your device. Downloads: JSON report and results CSV.",
  "implementation": {
    "fields": [
      {
        "key": "areaUnit",
        "label": "Area unit",
        "value": "m²",
        "type": "select",
        "values": [
          "m²",
          "ft²"
        ]
      },
      {
        "key": "area",
        "label": "Element area",
        "value": 100,
        "type": "number",
        "min": 0,
        "step": "any"
      },
      {
        "key": "beforeU",
        "label": "U-value before (W/m² K)",
        "value": 1.5,
        "type": "number",
        "min": 0,
        "max": 20,
        "step": "any"
      },
      {
        "key": "afterU",
        "label": "U-value after (W/m² K)",
        "value": 0.5,
        "type": "number",
        "min": 0,
        "max": 20,
        "step": "any"
      },
      {
        "key": "degreeDays",
        "label": "Heating degree days (K days)",
        "value": 2000,
        "type": "number",
        "min": 0,
        "max": 20000,
        "step": "any",
        "help": "Enter local Celsius/Kelvin degree days at a suitable balance temperature. Fahrenheit degree days must be divided by 1.8 first."
      },
      {
        "key": "performance",
        "label": "Heating efficiency fraction or seasonal COP",
        "value": 0.8,
        "type": "number",
        "min": 0,
        "max": 20,
        "step": "any",
        "help": "For example 0.8 for 80% efficiency, or 3 for a heat pump seasonal COP of 3."
      },
      {
        "key": "tariff",
        "label": "Fuel or electricity price per input kWh",
        "value": 0.1,
        "type": "number",
        "min": 0,
        "max": 100000,
        "step": "any"
      },
      {
        "key": "installedCost",
        "label": "Installed cost",
        "value": 3000,
        "type": "number",
        "min": 0,
        "max": 1000000000000,
        "step": "any"
      }
    ],
    "registrationFamily": "home-heating-costs",
    "input": false,
    "live": true,
    "presentation": "metrics",
    "note": "Calculated on your device. Enter the element area, before/after U-values and local heating degree days. This is a steady-state heating estimate for one element.",
    "experience": {
      "automatic": true,
      "single": true,
      "inputMaxLength": 1000000,
      "inputMode": "text",
      "label": "Heating assumptions",
      "placeholder": "Use the fields below",
      "help": "This calculator uses the fields below. Results update as you type. Up to 1,000,000 characters.",
      "helpParts": [
        "This calculator uses the fields below.",
        "Results update as you type.",
        "Up to 1,000,000 characters."
      ],
      "action": null
    },
    "mode": "automatic",
    "interactive": false
  },
  "execution": "Browser interface",
  "api": null,
  "browser_agent": {
    "supported": true,
    "name": "run_current_tool",
    "discovery": "WebMCP on the human page in a supporting browser",
    "verification": "See audit/API-AUDIT.md; availability is not verification"
  }
}

Page guide

Estimate annual heating energy and cost saved by changing an element’s U-value, using your local degree days, heating efficiency and installation cost.

How to use Insulation payback calculator
  1. Enter the insulated area and its whole-element U-values before and after the work.
  2. Enter local heating degree days in K days, heating efficiency or COP, and the price per input kWh.
  3. Enter installed cost and review annual energy and cost savings.
  4. Check the model boundaries before using simple payback, then download the JSON report or CSV.

Useful next steps

Appliance electricity cost calculatorHot water energy calculatorInsulation calculator

Annual heat transfer

The estimate uses U-value × area × heating degree days × 24 / 1000 to calculate useful heat in kWh. Use U-values for the whole element, including the construction layers you intend to compare. Enter local degree days at an appropriate balance temperature; Fahrenheit degree days must first be divided by 1.8.

From heat to cost

Useful heat is divided by heating efficiency or seasonal COP before applying the input-energy price. Enter 0.8 for 80% efficiency or 3 for a seasonal COP of 3. The example 100 m², U-values 1.5 and 0.5, and 2,000 K days saves 4,800 useful heat kWh.

Simple payback limits

Simple payback is installed cost divided by positive annual cost saving. Equal or worse U-values and zero tariffs can produce no payback or a negative saving. The model excludes cooling, thermal bridges, air leakage, solar gains, behavioural changes, grants, finance and tariff changes.