Reading the labels.
WHAT RATINGS TELL YOU
Relative efficiency, within a category.
WHERE THEY APPEAR
Air conditioners Refrigeration Motors Lighting
WHY THEY MATTER FINANCIALLY
An efficient unit costs more to buy and less to run; the difference compounds over years.
HOW TO COMPARE PROPERLY
Purchase price plus running cost over the expected life.
HOW TO ESTIMATE RUNNING COST
Wattage, multiplied by hours used annually, divided by a thousand, multiplied by your cost per unit.
WHY YOUR COST PER UNIT MATTERS
At generator prices, efficiency pays back far faster than at grid prices.
WHAT INVERTER AIR CONDITIONERS DO
Vary compressor speed rather than switching on and off.
WHAT THAT PROVIDES
Lower consumption, particularly for long running periods, and gentler starting current.
WHY GENTLER STARTING MATTERS HERE
It makes them viable on generators and inverter systems that fixed-speed units would overwhelm.
WHAT TO CHECK IN LIGHTING
Lumens rather than watts.
WHY
Lumens measure light produced; watts measure energy consumed.
WHAT TO LOOK FOR IN MOTORS
Efficiency class, where stated.
WHAT TO BE SCEPTICAL OF
Claims with no standard behind them Ratings on unbranded equipment
WHAT TO DO BEFORE BUYING ANY MAJOR APPLIANCE
Calculate its annual running cost at your actual energy price.
WHAT THAT FREQUENTLY CHANGES
Which model is genuinely cheaper.
