COP and EER converter
Convert heat pump and AC efficiency between COP, EER and kW per ton.
That's 1.1× as efficient as an air-source heat pump, while a modern split air conditioner is 1.08× more efficient. Every kWh of electricity moves 3.517 kWh of heat.
What it means
How efficient is that?
These are steady-state ratings. Seasonal figures such as SEER and SCOP average over a whole year of weather and cannot be converted exactly from a single rating.
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Three things worth knowing
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EER = COP × 3.41
An EER of 12 is a COP of 3.5. A chiller at 0.6 kW per ton is a COP of 5.9.
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Beating 100%
An electric heater turns every kWh into exactly one kWh of heat, 100% efficient. A heat pump at COP 4 delivers 400%, because most of the heat comes from outside air or the ground.
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EER is not SEER
SEER averages over a cooling season and usually reads higher than EER for the same unit. Converting one to the other with a fixed factor is only a rough guide.
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Background
About COP and EER
A heat pump or air conditioner does not make heat; it moves it. The coefficient of performance, COP, is how many units of heat move for each unit of electricity: a COP of 3 turns 1 kWh of electricity into 3 kWh of heating or cooling.
The US quotes the same thing as EER, in BTU of cooling per watt-hour, and large chiller plants in kW per ton, which runs the other way.