Picking an efficiency level for a mild climate
Furnace efficiency is rated in AFUE, the share of fuel that becomes heat. Typical price steps from our guide:
| AFUE rating | Tier | Added to base price |
|---|
| 80 percent | Standard efficiency | Base price |
|---|
| 90 to 92 percent | Mid efficiency condensing | Add $400 to $900 |
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| 95 to 96 percent | High efficiency | Add $900 to $1,800 |
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| 97 to 98 percent or more | Premium modulating | Add $2,200 to $4,000 |
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The extra cost of a higher AFUE rating pays back through lower gas use, and the payback depends on how many hours you run the furnace. In colder places that can be a few years.
In Bakersfield, where the furnace runs far fewer hours, it takes longer, so the mid efficiency tiers are often the best value. A premium modulating furnace is worth it for comfort and quiet, not usually for the gas savings.
We run the comparison with you.