Air-conditioning efficiency ratings

Fixed reversible AC product data can include EER and SEER for cooling, with COP and SCOP for heating. These figures describe different rating methods. They should not be combined or compared without checking the test basis and product configuration.

EER and COP

EER is the ratio of cooling output to electrical input at stated rating conditions.

COP is the equivalent point-condition ratio for heating. It compares heat output with electrical input at the stated indoor and outdoor test conditions.

Both are point-condition figures. The values also need to cover the same system combination if two products are being compared.

SEER and SCOP

SEER is a seasonal cooling metric calculated under the applicable product test methodology. SCOP is the corresponding seasonal heating metric.

Comparable values need the same test method, climate basis and product configuration. A figure for one indoor and outdoor pair should not be assigned to a different multi-split combination without supporting manufacturer data.

Nominal, minimum and maximum capacity

Product tables can list nominal, minimum and maximum capacity separately. These values are not interchangeable.

Capacity in kW and efficiency as a ratio are separate fields.

Energy labels

Domestic air conditioners within the applicable scope carry energy information based on standardised testing. Current manufacturer pages may show separate cooling and heating classes alongside SEER and SCOP. Panasonic states that its seasonal labels use the A+++ to D scale and that its EER and COP figures use EN 14511.

The label helps compare declared product performance on the same basis. It cannot account for the building’s load, weather, the selected set point, controls, installation quality, cycling, defrost or user behaviour.

Heating performance estimates

MCS 031 b states that a performance estimate is not a detailed design. It also warns against treating estimates for different MCS technology types as direct one-to-one comparisons.

Rating data for a complete system

The rating record for a complete system contains:

• the exact indoor and outdoor unit combination
• nominal cooling and heating capacity
• the stated conditions for EER and COP
• SEER and SCOP with their climate or test basis
• cooling and heating energy classes
• minimum and maximum capacity ranges

Related entries

• Air-conditioning cooling load and sizing
• Single-split and multi-split air conditioning
• Air-to-air heat pumps
• SCOP performance estimate