Manual J Calculations Add 10 Years to Unit Lifespan Through Accurate Sizing
https://telegra.ph/Five-Thousand-Dollar-Thresholds-Define-When-Repair-Costs-Justify-System-Replacement-Decisions-08-13
An HVAC system typically lasts 15 to 20 years, but correct Manual J load calculation and proper tonnage sizing can add a full decade to that lifespan