European Union Eco-Label

The European Eco-label is a voluntary scheme enabling European consumers including public and private purchasers to easily identify officially approved green products across the European Union, Norway, Liechtenstein and Iceland.

http://europa.eu.int/comm/environment/ecolabel

Energy +

The Energy+ project brings together retailers, institutional buyers and European institutions eager to purchase and promote the most energy-efficient four-star refrigerator-freezers on the market. Energy+ appliances use three-quarters, or less, of the energy of equivalent appliances meeting the minimum class A requirement under the European energy labelling scheme.

www.energy-plus.org

Energy Star Label

In the EU, the standard covers the office equipment sector, including computers, printers and scanners. The EU ENERGY STAR database enables the most energy efficient models for certain performance criteria to be selected.
www.eu-energystar.org/en/en_database.htm 
In the US, the label covers a much wider range of products. 

www.energystar.gov

APEC Energy Standards Information System

The APEC Energy Standards Information System (ESIS) web site provides comprehensive detail on testing standards, MEPS, and labelling requirements for countries in the Asia-Pacific region.

www.apec-esis.org

Collaborative Labelling and Appliance Standards Program (CLASP)

The CLASP provides background details on energy labelling standards and programmes on a global basis.

www.clasponline.org

Boiler Efficiency Database

This UK Government supported database contains data on the average annual efficiency achieved by gas and oil boilers in typical domestic conditions.

www.boilers.org.uk