Lennox offers the highest efficiency on the market, with models reaching 99% AFUE .
The Best Energy‑Efficient Furnaces: Brand Comparisons & Top Picks what is the best natural gas furnace to buy
The "best" natural gas furnace to buy depends entirely on your specific priority—whether that is long-term reliability, maximum energy savings, or upfront affordability. For 2026, is widely regarded as the best overall choice due to its industry-leading reliability and performance in extreme cold. However, other brands excel in specific categories: Lennox offers the highest efficiency on the market,