chaudière au fioul à haut rendement

OBS: fioul : Cette graphie, puisée des Rectifications de l'orthographe recommandées par le Conseil supérieur de la langue française, est attestée dans le Petit Robert (2004).

CONT: High Efficiency Oil Furnace ... Essentially, oil furnace efficiency is measured in AFUE ratings. That stands for Annual Fuel Utilization Efficiency. And, the AFUE rating equals the percent efficiency the unit delivers. The higher the percentage the more efficient the unit.
CONT: Oregon Oil Heat Commission provides a $300 cash incentive for property owners to conserve fuel by purchasing a new high-efficiency oil furnace.