ACHR News asked a number of HVAC contractors how they know when it’s time to replace an old HVAC unit. The scenario, as well as the unit’s age, condition, and replacement cost, all play a role in the answer. “The staff at Walnut Creek Heating & Air Conditioning, Walnut Creek, California, estimates a unit that has been repaired more than twice in the last 10 years, is under a 13 SEER rating, or is 12 years old or older should be replaced,” says Nick Kostora. When the scenario dictates a full system replacement, make sure you have all the facts about the latest heating technologies. Taking A Comparative Analysis of Residential Heating Systems at the Propane Training Academy is an excellent way to make sure you’re up to date.