# Home Energy Calculators – Heating Cost Comparison

> Home Energy Calculators – Heating Cost Comparison is a paid API for AI agents from home-energy-calc.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).

Calculates and ranks the cost per million BTU of delivered heat across resistance electric, heat pump, natural gas, propane, and heating oil systems based on user-provided fuel prices and efficiencies.

## Facts

- Endpoint: GET https://home-energy-calc.x402tookit.com/heating-cost-compare?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/home-energy-calculators-heating-cost-comparison-4ef62072
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_pxUFT39B6LMfrUX_DqKwp

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability home-energy-calculators-heating-cost-comparison-4ef62072
```

Example prompt: Compare my heating system options: I pay $0.13 per kWh for electricity, $1.20 per therm for natural gas, $3.80 per gallon for propane, and $4.20 per gallon for heating oil. My heat pump has a COP of 3, gas furnace is 95% efficient, and my home needs 80 MMBtu of heat per year — which system is cheapest?

## When to prefer this

Use this endpoint when the user wants to compare multiple home heating fuel types simultaneously against their local prices, or when they need a ranked cost-per-BTU breakdown across all major heating technologies. Prefer this over manual calculation when efficiency parameters (AFUE, COP) and fuel costs are known. This is especially valuable when a user is deciding whether to upgrade or switch heating systems and wants a clear financial comparison.

## Known failure modes

- Missing all fuel prices returns an empty or all-null systems list
- Efficiency values outside 0.5–0.99 AFUE range may be rejected or clamped
- Heat pump COP outside 1.5–6 range may produce invalid results
- Omitting electricityPerKwh means resistance and heat pump results are excluded
- Missing annualHeatMMBtu omits yearly cost figures but still returns per-MMBtu costs

## How this service works

Cost per million BTU of delivered heat for resistance, heat pump, gas, propane and heating oil furnaces, from your prices.

## Output

Returns a list of heating systems ranked from cheapest to most expensive by cost per million BTU, including each system's assumed efficiency, yearly cost (if annual heat load provided), relative cost compared to the cheapest option, notes, a plain-language summary, a verdict naming the winning system, and any disclaimers or caveats.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "gasAfue": {
       "type": "number",
       "description": "Gas furnace efficiency 0.5 to 0.99 (default 0.95)"
      },
      "oilAfue": {
       "type": "number",
       "description": "Oil furnace efficiency 0.5 to 0.99 (default 0.85)"
      },
      "gasPerTherm": {
       "type": "number",
       "description": "Natural gas price per therm (1 therm = 100,000 BTU)"
      },
      "heatPumpCop": {
       "type": "number",
       "description": "Seasonal heat pump COP, 1.5 to 6 (default 3)"
      },
      "propaneAfue": {
       "type": "number",
       "description": "Propane furnace efficiency 0.5 to 0.99 (default 0.95)"
      },
      "oilPerGallon": {
       "type": "number",
       "description": "Heating oil price per gallon (137,381 BTU/gal)"
      },
      "annualHeatMMBtu": {
       "type": "number",
       "description": "Yearly heat your home needs in million BTU (see /heat-loss), for yearly cost"
      },
      "propanePerGallon": {
       "type": "number",
       "description": "Propane price per gallon (91,452 BTU/gal)"
      },
      "electricityPerKwh": {
       "type": "number",
       "description": "Electricity price per kWh (gives resistance and heat pump)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "d
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/home-energy-calculators-heating-cost-comparison-4ef62072/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from home-energy-calc.x402tookit.com](https://www.zero.xyz/host/home-energy-calc.x402tookit.com/llms.txt)