HomeAnswersIs a high-efficiency furnace worth it in northern Wisconsin?
Is a high-efficiency furnace worth it in northern Wisconsin?
What the efficiency number actually measures
AFUE is the share of fuel turned into heat over a season. An 80 percent furnace sends roughly a fifth of the fuel up the flue. A condensing furnace recovers most of that and rates above 90 percent. In a climate with a long heating season, that gap shows up in real dollars.
The part nobody mentions: venting
A condensing furnace produces acidic condensate and vents through PVC, which means a drain path and often a new vent route. If your house has an old metal flue and no practical route for the new vent, installation cost can eat the fuel savings for years.
When the upgrade clearly pays
You are already replacing a failed furnace, you plan to stay in the house more than a decade, and the vent route is simple. Then the marginal cost of condensing over 80 percent is usually the cheapest efficiency you will ever buy.
When it does not
You are replacing a working furnace purely for efficiency, the vent route is difficult, or you are moving within a few years. Efficiency gains are earned over seasons, not at resale.
Ask for annual fuel use, not a payback promise
A contractor can estimate your seasonal fuel use from house size, insulation, and the old unit's rating. That estimate is worth more than a promised payback figure, which depends on gas prices nobody controls.