{
    "name": "Heat Pump COP Calculator",
    "url": "https://calculators.geekmidst.com/calculators/heat-pump-cop-calculator",
    "markdown": "https://calculators.geekmidst.com/calculators/heat-pump-cop-calculator.md",
    "category": "Energy & environment",
    "description": "Work out a heat pump’s coefficient of performance from heat output and electrical input, compare it with the Carnot limit and estimate yearly running cost.",
    "summary": "COP is heat delivered divided by electricity used: a COP of 3 gives 3 kWh of heat per kWh of electricity. The Carnot limit shows the theoretical best for your temperatures.",
    "also_called": [
        "Coefficient of performance calculator",
        "Heat pump efficiency calculator"
    ],
    "applies_to": "Worldwide",
    "last_updated": "2026-10-29",
    "computation": "Results are computed in the visitor’s browser on the HTML page. This API describes the calculator; it does not compute results.",
    "inputs": [
        {
            "name": "heat_kw",
            "label": "Heat output",
            "type": "number",
            "default": "8",
            "unit": "kW"
        },
        {
            "name": "power_kw",
            "label": "Electrical input",
            "type": "number",
            "default": "2.5",
            "unit": "kW"
        },
        {
            "name": "flow_c",
            "label": "Output (flow) temperature",
            "type": "number",
            "default": "35",
            "unit": "°C"
        },
        {
            "name": "source_c",
            "label": "Source temperature (outdoor air or ground)",
            "type": "number",
            "default": "5",
            "unit": "°C"
        },
        {
            "name": "annual_heat",
            "label": "Heat needed per year",
            "type": "number",
            "default": "10000",
            "unit": "kWh",
            "optional": true
        },
        {
            "name": "price",
            "label": "Electricity price per kWh",
            "type": "number",
            "default": "0.25",
            "optional": true
        },
        {
            "name": "currency",
            "label": "Currency",
            "type": "currency",
            "default": "USD"
        }
    ],
    "outputs": [
        {
            "key": "cop",
            "label": "Coefficient of performance (COP)",
            "format": "number"
        },
        {
            "key": "carnot_cop",
            "label": "Carnot (ideal) COP",
            "format": "number"
        },
        {
            "key": "carnot_pct",
            "label": "Share of the Carnot limit achieved",
            "format": "percent"
        },
        {
            "key": "annual_elec_kwh",
            "label": "Electricity per year at this COP",
            "format": "number"
        },
        {
            "key": "annual_cost",
            "label": "Running cost per year at this COP",
            "format": "currency"
        }
    ],
    "formula": {
        "text": "COP = Heat output ÷ Electrical input;  COP(Carnot) = T_hot ÷ (T_hot − T_cold) in kelvin;  Electricity per year = Heat needed ÷ COP",
        "variables": {
            "T_hot": "output temperature + 273.15",
            "T_cold": "source temperature + 273.15"
        }
    },
    "worked_example": {
        "inputs": {
            "heat_kw": "8",
            "power_kw": "2.5",
            "flow_c": "35",
            "source_c": "5",
            "annual_heat": "10000",
            "price": "0.25",
            "currency": "USD"
        },
        "steps": [
            "COP = 8 ÷ 2.5 = 3.2.",
            "Carnot COP = 308.15 ÷ (35 − 5) = 10.27, so the unit reaches 3.2 ÷ 10.27 = 31.15% of the ideal.",
            "Yearly electricity = 10,000 ÷ 3.2 = 3,125 kWh × 0.25 = 781.25."
        ],
        "result": "Delivering 8 kW of heat from 2.5 kW of electricity is a COP of 3.2, so 10,000 kWh of heat costs about 781 a year."
    },
    "interpretation": "COP falls as the gap between source and output temperature grows, which is why low flow temperatures (larger radiators, underfloor heating) improve efficiency. A single COP measurement is a snapshot; the seasonal average (SCOP) is what sets yearly cost.",
    "assumptions": [
        "The COP entered applies to the whole year when estimating running cost."
    ],
    "limitations": [
        "Defrost cycles, backup heaters and pump energy reduce real seasonal efficiency."
    ],
    "rules": null,
    "faqs": [
        {
            "question": "What is the difference between COP and SCOP?",
            "answer": "COP is measured at one set of conditions; SCOP (seasonal COP) averages performance across a heating season and is the better guide to annual cost."
        },
        {
            "question": "Can COP be higher than the Carnot COP?",
            "answer": "No. If a measurement exceeds it, the heat or power readings are wrong."
        }
    ],
    "sources": [],
    "related": [
        {
            "name": "Home Electricity Bill Calculator",
            "url": "https://calculators.geekmidst.com/calculators/home-electricity-bill-calculator"
        },
        {
            "name": "Carbon Emissions Calculator",
            "url": "https://calculators.geekmidst.com/calculators/carbon-emissions-estimate-calculator"
        },
        {
            "name": "Temperature Converter",
            "url": "https://calculators.geekmidst.com/calculators/temperature-converter"
        }
    ],
    "disclaimer": null,
    "publisher": "GM¹X CalcVerse"
}