Heat pump cost to run

Heat pump cost to run needs electricity use over a period, or a heat-demand case with COP and backup assumptions. The worksheet above supports both. It gives an editable US rate reference. It is not your tariff. Heat delivered stays separate from power already metered.

Known-kWh mode multiplies input power use by rate without another COP division. Demand mode converts delivered heat to power use, divides the pump share by COP and adds declared resistance backup. Keep the period, terms and source. Low cost uses low demand, high COP and low rate. High cost uses the opposite endpoints. Fixed charges, cooling and unknown auxiliary use remain outside the heating use estimate.

Heat pump cost to run: choose the period and mode

Use a period that matches the data. A month of metered kWh and a yearly heat-demand estimate should not be compared without a clear time basis. The result shows the period.

The EIA energy reference gives the unit conversion. A heat rate in BTU/h is not a heat quantity over a month. Do not multiply design load by all hours and call it measured demand.

Heat delivered versus electricity used

COP is heat delivered divided by power input in matching units. It describes a stated performance scope. It is not a fixed yearly value implied by every heat-pump badge.

Known metered kWh is already input energy. Dividing it by COP would reduce the purchased power use twice. Demand mode needs COP because its input is heat, not power use.

COP and backup assumptions

Use a COP range with stated period and temperature context. Do not derive it from a SEER2 cooling label. Seasonal heating ratings and one-state COP are separate records.

The ENERGY STAR air-source page gives official low-temperature performance context. The selected full model needs its own data. The cold-climate guide keeps capacity and backup apart.

The backup field is the share of delivered heat from resistance elements. Zero is a declared case, not proof that backup never runs. A gas-furnace backup requires a separate fuel comparison. It is not modelled as resistance power use here.

Heat pump cost to run: formulas

For demand mode, convert delivered BTU to kWh of heat using approximately 3,412 BTU/kWh. Pump power use equals the pump heat share divided by COP. Resistance backup adds its heat share without the pump COP divisor.

For known-input mode, multiply kWh by USD/kWh. Do not adjust known input by efficiency again. Both modes preserve the period and source statement.

A labelled operating scenario

Suppose delivered heat is 50,000,000 BTU over a declared period, COP is 3 and resistance backup share is zero. The derived input is about 4,884.72 kWh. At the historical EIA reference of 0.173 USD/kWh, usage cost rounds to $845.

These are example inputs, not measured heat use at your home. The tool requires your demand and COP source before generating its result. No yearly demand or universal COP is silently supplied.

The comparison shows sensitivity to bases. It does not predict which backup share an actual model will use. Retain the design and control evidence for that question.

Rates, weather and bill boundaries

The default is EIA's 2025 US residential average electricity rate, checked October 14, 2026. It remains editable. It is historical national context, not your current marginal tariff.

Use the actual billed usage rate where known. Keep fixed service charges separate. If rates vary by time or tier, use a supported rate for that period. One US reference cannot capture every tariff.

Weather can alter heat need. It can alter COP too. Two months with the same rate can have different use. A changed bill does not prove the unit rating changed.

Read a meter and compare scenarios

Check what the meter serves. A whole-home meter includes other appliances. A dedicated system meter can have a narrower scope. Keep that limitation in the source field rather than calling all purchased power use heating.

Use the same heat demand when comparing technology cases. Change the COP or backup basis to examine its effect. Do not change demand as well and attribute the whole difference to one unit feature.

Keep input energy and heat demand on different lines

Write metered kWh on the input line. Write estimated heat delivered on the demand line. Do not move the same number between them without a stated conversion.

COP connects those quantities for a performance case. It does not reduce power use already bought and measured. This is why the two modes use different formulas.

When comparing months, retain each period's rate and source. When comparing unit cases, retain equal heat demand. These boundaries stop a change in weather or meter scope from being described as a checked unit saving.

FAQ

Why not multiply the heat pump's maximum power by every hour?

That shortcut assumes the unit operates at maximum input continuously. It ignores load variation, controls and the period's terms. Use metered energy where available or a sourced heat-demand case with COP. A maximum power rating can help describe the unit. But it is not by itself a yearly heating-energy record for the house.

Does a high SEER2 give me annual heating COP?

No. SEER2 is a seasonal cooling rating, while COP describes a stated heat and power-input scope. Heating terms and the full match need their own evidence. Do not insert a COP inferred from a cooling number. Keep the performance source and period with the worksheet before comparing yearly or monthly heating costs.

Does the zero backup default prove no strips will run?

No. It is a visible declared case. The actual load, low-temperature capacity and controls determine the real contribution. Enter a supported share where known, and retain its source. The worksheet does not guarantee zero resistance use or approve a backup setup from a rated outdoor size or seasonal efficiency label alone.

Does the output include the whole utility bill?

No. It is the heating-energy usage cost for the stated input scope. Fixed charges, other appliances, cooling and unknown auxiliary use are excluded. Replace the national reference with your applicable rate and keep the meter scope clear. A heating case should not be described as the full bill while those other costs remain outside it.

When you use meter data, keep the meter boundary with the period. A whole-house electric total can include cooling and other loads. State that scope before treating it as heat-pump use. The tool prices the given kWh; it does not separate appliances for you.

Verdict: keep heat pump cost to run tied to the period and input boundary

Heat pump cost to run becomes useful when heat demand, COP, backup and rates are explicit. Print the bases with the result. Return to heat pump installation prices for a separate purchase budget.