How this calculator works
COP measures heat moved per unit work, so it can exceed one without creating energy. A cyclic device satisfies Qh = Qc + W, giving heating COP exactly one greater than cooling COP when both describe the same boundary and operating point. Carnot COP is the reversible upper limit for the specified reservoirs, not a rating for real equipment. Energies may be replaced by consistent steady rates when forming a ratio.
Formula
COPr = Qc/W; COPhp = Qh/W = COPr + 1; Carnot COPr = Tc/(Th - Tc), COPhp = Th/(Th - Tc).
Worked example
A device removing 1000 J while using 200 J of work delivers 1200 J, with cooling COP 5 and heating COP 6. The reversible limits between 250 K and 300 K are also 5 and 6.
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Frequently asked questions
Can COP be greater than 100%?
COP is a ratio of moved heat to work, not conversion efficiency; values above one are normal.
What happens when reservoir temperatures match?
The ideal expression diverges. A finite practical device still needs a temperature difference and other constraints.
Can I compare heating and cooling labels directly?
Only when they use the same operating conditions and account for the same auxiliary inputs.