To elaborate on the "yes": SEER is a ratio of energy expended to energy moved. So SEER 13 means that the system spends one unit of energy to move 13. And you sh

To elaborate on the "yes": SEER is a ratio of energy expended to energy moved. So SEER 13 means that the system spends one unit of energy to move 13. And you should expect a SEER 20 system to be twice as efficient as a SEER 10 system. EDIT: I should mention that SEER uses different units for each part of the ratio -- BTUs of heat moved vs watt-hours expended. COP is dimensionless, and EER is just SEER but for a specific operating point. SEER extends the measurement through an entire "season", and so it theoretically gives a more realistic picture of overall efficiency.