Furnace Replacement Glossary

Plain-English explainers for the technical terms, rebates, regulations, and acronyms that show up when you shop for Furnace Replacement systems and services. Each entry links the underlying source, lists the numbers that matter, and points to related concepts.

AFUE (Annual Fuel Utilization Efficiency)
The efficiency score of a gas furnace — how much of the fuel you pay for actually becomes heat in your home.
The 2028 Federal Furnace Standard (95% AFUE Rule)
From December 2028 every new non-weatherized gas furnace must be 95% AFUE — why replacing now means buying ahead of the rule.
Furnace Venting Category & the Orphaned Water Heater
Why upgrading an 80% furnace to a 95% one means new plastic venting — and the water-heater safety check that's easy to skip.
Gas Furnace vs. Heat Pump (the Replacement Decision)
The fork in the road at replacement time: another gas furnace, an all-electric heat pump, or a dual-fuel hybrid of both.
Manual J Load Calculation (Furnace Sizing)
The heat-loss calculation that decides your furnace's BTU size — the fix for the oversized furnace that short-cycles and swings the temperature.
Single-Stage, Two-Stage & Modulating Furnaces
How many 'gears' a furnace burns at — the comfort-and-efficiency tier behind the price gap between two new units.
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