The answer to 'single stage vs two stage furnace' is that a two-stage furnace is generally more energy-efficient and provides better temperature control compared to a single-stage furnace. Two-stage furnaces have a high and low heating setting, allowing them to run at a lower, more efficient level when the home doesn't require maximum heating power. This results in lower energy bills and more consistent, comfortable temperatures throughout the home.
Single-stage furnaces only have one heating setting, so they run at full capacity even when the home doesn't need that much heat. This can lead to temperature swings and higher energy consumption. Two-stage furnaces are more expensive upfront, but the energy savings over time often make up for the higher initial cost.