How do you calculate defrost energy cost?

Multiply defrost electricity use by the electricity rate and the operating scope, then add the fixed service cost. At 18,000 kWh, $0.11/kWh, 100% scope and $1,200 fixed, that is $1,980 variable plus $1,200, or $3,180 total.

What counts as defrost electricity use?

The kWh consumed specifically by defrost events — reverse-cycle compressor energy, electric defrost heaters, fan operation during the cycle, and any auxiliary heat used to recover. It excludes normal heating-mode energy.

Why does defrost cost matter for a heat pump?

Defrost is parasitic — it spends energy without delivering process heat and interrupts heating. In humid, near-freezing conditions it can consume several percent of total input, eroding the COP advantage that justified the electrified system.

Will demand-defrost controls reduce this cost?

Usually yes. Time-and-temperature defrost often triggers cycles the coil does not need. Demand-defrost that senses actual frost can cut defrost events substantially, directly shrinking the variable kWh term in this calculation.

What is the fixed defrost service cost?

It covers the non-energy upkeep of the defrost system over the period — sensor checks, reversing-valve and hot-gas component maintenance, and controls calibration. It is roughly constant regardless of how many kWh defrost consumes.

Why include an operating scope percentage?

Scope lets you charge only the portion of defrost energy attributable to this unit or season. Use 100% for the full figure, or less to isolate one operating mode or to share cost across systems.

Industrial Heat Pumps & Electrified Thermal Systems calculator

Air-Source Heat Pump Defrost Energy Cost Calculator

Defrost energy cost quantifies the parasitic electricity an air-source industrial heat pump burns to shed frost from its evaporator coil, plus the fixed service cost of keeping the defrost system healthy. Frost on the coil chokes airflow and tanks the COP, so the unit must periodically reverse, use electric heat, or run hot-gas defrost — all of which consume energy that does no useful process heating. Energy and facilities engineers track this because in cold, humid climates defrost can quietly erase a meaningful slice of the seasonal efficiency that justified the heat pump in the first place. Putting a dollar figure on it lets you compare demand-defrost controls, coil coatings, and service contracts on the same basis.

What this calculator does

Estimate seasonal defrost operating cost for an air-source industrial heat pump from defrost kWh, electric tariff, scope share, and fixed service cost.
Use it when energy or maintenance teams are reviewing cold-climate air-source heat pumps, outdoor process hot water skids, or frost-prone heat recovery equipment.
It computes the total dollar cost of defrost operation by multiplying defrost electricity use by the electricity rate and the operating scope, then adding the fixed defrost service cost.

Formula used

Variable defrost energy cost = defrost electricity use × electricity cost × defrost operating scope
Total defrost energy cost = variable defrost energy cost + fixed defrost service cost

Inputs explained

Defrost electricity use:
Electricity cost:
Defrost operating scope:
Fixed defrost service cost:

How to use the result

Use it when evaluating demand-defrost controls, sizing the parasitic load in a seasonal efficiency model, or budgeting the running cost of an air-source industrial heat pump.
Defrost kWh varies sharply with ambient humidity and temperature; a single period figure will not represent a milder or harsher season without re-running with that season's data.

Current U.S. benchmarks

As of Apr 2026, industrial electricity averages 8.7 cents per kWh across the U.S. (EIA), up 5.5% from a year earlier. State averages range widely, so plants should confirm against their own tariff.
Global copper trades at $13,484 per tonne (IMF via FRED, May 2026), up 41.5% in a year, and U.S. industrial electricity averages 8.66 cents per kWh. Both feed electrified-hardware unit economics.
The U.S. has 21,668 machinery manufacturing establishments employing about 1,086,146 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate defrost energy cost? Multiply defrost electricity use by the electricity rate and the operating scope, then add the fixed service cost. At 18,000 kWh, $0.11/kWh, 100% scope and $1,200 fixed, that is $1,980 variable plus $1,200, or $3,180 total.
What counts as defrost electricity use? The kWh consumed specifically by defrost events — reverse-cycle compressor energy, electric defrost heaters, fan operation during the cycle, and any auxiliary heat used to recover. It excludes normal heating-mode energy.
Why does defrost cost matter for a heat pump? Defrost is parasitic — it spends energy without delivering process heat and interrupts heating. In humid, near-freezing conditions it can consume several percent of total input, eroding the COP advantage that justified the electrified system.
Will demand-defrost controls reduce this cost? Usually yes. Time-and-temperature defrost often triggers cycles the coil does not need. Demand-defrost that senses actual frost can cut defrost events substantially, directly shrinking the variable kWh term in this calculation.
What is the fixed defrost service cost? It covers the non-energy upkeep of the defrost system over the period — sensor checks, reversing-valve and hot-gas component maintenance, and controls calibration. It is roughly constant regardless of how many kWh defrost consumes.

Last reviewed 2026-05-12.