The concept of the "high-efficiency furnace" in popular consciousness dates back to the 1980s. That's when the National ...

Some HVAC pros prefer to call it routine maintenance. Whatever you call a tune-up, it keeps your furnace in top shape and ...

Mid-efficiency furnaces, which were common between 1990 and 2010, are up to 82 per cent efficient, so it’s like paying for ten apples and getting eight. In contrast, high-efficiency furnaces are ...