This article relies largely or entirely on a single source. (August 2011)
In Europe, the seasonal efficiency of refrigeration equipment, chillers and air conditioners is often rated by the European seasonal energy efficiency ratio (ESEER) which is controlled (among others) by the Eurovent Certification Company. A similar standard in the United States is the integrated energy efficiency ratio (IEER).
The ESEER is calculated by combining full and part load operating Energy Efficiency Ratios (EER), for different seasonal air or water temperatures, and including for appropriate weighting factors. These values are shown in the following table.
|Partial load ratio||Air temperature (°C)||Water temperature (°C)||Weighting coefficients|
The formula for ESEER can then be presented as follows:
- ESEER = (EER@100% load × 0.03) + (EER@75% load × 0.33) + (EER@50% load × 0.41) + (EER@25% load × 0.23)
Eurovent publishes EER and ESEER values in its Directory of Certified Products together with cooling capacity and power input for standard conditions at full load for a wide variety of commercially available equipment.
UK Building Regulations Part L SEER
In the United Kingdom, a Seasonal Energy Efficiency ratio (SEER) for refrigeration and air conditioning products, similar to the ESEER but with different load profile weighting factors, is used for part of the Building Regulations Part L calculations within the Simplified Building Energy Model (SBEM) software, and are used in the production of Energy Performance Certificates (EPC) for new buildings within the UK and the European Union; both as part of the European directive on the energy performance of buildings (EPBD).
The formula for SEER can be presented as follows:
- SEER = a (EER@25% load) + b (EER@50% load) + c (EER@75% load) + d (EER@100% load)
where a,b,c,& d are the load profile weighting factors relevant to the proposed application.
- Seasonal energy efficiency ratio, the American definition and calculation of seasonal energy efficiency ratios
- "Eurovent Paper: Effect of the Certification on Chillers Energy Efficiency" (PDF). Eurovent. 2006.[dead link]
-  Department for Communities and Local Government: Non Domestic Heating, Cooling and Ventilation Compliance Guide
- A new measure for the energy efficiency of heating and cooling devices - Information from Daikin on seasonal efficiency