110,000 BTU Modulating Gas Furnace 97% AFUE vs 88,000 BTU Modulating Gas Furnace 97% AFUE

Both are 97% AFUE modulating furnaces with ECM variable-speed blowers, the same cabinet footprint and the same propane kit requirement, so the real choice is capacity. The 110,000 BTU unit moves roughly 1,988 CFM and suits larger or leakier homes and colder climates; the 88,000 BTU unit at about 1,362 CFM fits a mid-size, well-insulated house and will modulate down further without short-cycling. Build and controls are otherwise identical, and owners of this class of furnace praise the steady heat and quiet variable-speed operation while noting the non-communicating controls limit smart-thermostat features.

• Choose the 110,000 BTU furnace if your load calculation calls for more than about 85,000 BTU of output, or you have a large, open or poorly insulated home in a cold climate.
• Choose the 88,000 BTU furnace if a load calculation puts your home near or below 85,000 BTU of output and you want longer, gentler low-fire cycles.