It said more than half of consumers consider sustainability when buying appliances. So the consumer champions began the new Eco Buy scheme last year endorsing items with the least environmental impact.
Many householders assume eco-friendly appliances will be pricy but the Beko Aeroperfect electric oven is just £179.
It costs just £44 a year to run – a £16 annual saving on the most inefficient ovens.
Which? research also found there is a 10-year difference between the models with the shortest and longest lifespans.
Fridge-freezers consume a lot of electricity and can add up to £163 a year to energy bills.
But the group said the £471 Eco Buy Liebherr model costs £41 a year to run – a £120 saving compared to the most energyhungry fridge-freezer.
It also endorsed a £328 Hotpoint tall larder fridge.Tumble-dryers can add around £100 to energy bills every year.
So only more energy-efficient heat pump dryers will be eligible for an Eco Buy award.
While heat-pump dryers tend to be more expensive initially, an Eco Buy Samsung tumble dryer only adds £30 to energy bills a year – a £60 saving on energy-hungry condenser models, which could cost £90 to run.
The Government is set to introduce new rules this summer that will require manufacturers to make spare parts for appliances available to help tackle premature obsolescence and reduce carbon emissions.
Michael Briggs, of Which?, said: “Consumers want to reduce their carbon footprint and make more sustainable choices.
“That is why we are evolving the way we test products, factoring in how long they last and their energy efficiency.”
The green machines:
Hotpoint SH61QW1 Fridge – £328
Liebherr CNEL4713 Fridge Freezer – £471
Blomberg ODN9302X Double Oven – £530
Beko BBXIF22100S AeroPerfect Oven – £179
Samsung DV80TA020AE/EU Tumble Dryer – £599
AEG T7DBK841N Tumble Dryer – £649