How Efficient Is a 20-Year Old-Furnace? Stats on EfficiencySimply put, the most efficient way to answer a question about furnace efficiency is to take a look at some stats. Here are a couple of key numbers to know:
- 20-year-old furnaces have an annual fuel utilization efficiency, or AFUE, of 78% or less, according to the U.S. Department of Energy. AFUE is the basic energy efficiency rating system used in the HVAC industry. A 78% AFUE furnace uses 78% of the energy it consumes to heat the air that makes it into your home, while the other whopping 22% is lost to inefficiency.
- On average, a new furnace has a 95% AFUE, making it roughly 17% more efficient than a 20-year-old one.
How Efficient Is a 20-Year-Old Furnace? Signs to Tell If Yours Is Wearing OutIf you’re a mechanical guy like me, you tend to form some strange relationships with your trusty cars and appliances. Maybe I’m exaggerating a bit but, looking back, I think some of the saddest moments in my life have been saying goodbye to cars or furnaces that served me well over the years. AIn every one of these cases, there were always signs warning me that my old friend was getting long in the tooth and wouldn’t be with me much longer. Furnaces have a way of telling us that their time in our lives is just about up. I should note here, too, that these are the signs that your furnace is still working, but isn’t as efficient as it should be, which are different than signs that your furnace needs repair. Here are some common signs that your furnace has become inefficient:
- Your gas bill is higher than in previous years: This is the headliner here. If your gas bill is higher than it has been in the past, then there’s a very good chance that your furnace has dipped in its efficiency. See, gas bills tend to rise without explanation when a furnace has to start running more to generate the same amount of heat, which is practically the definition of being inefficient.
- You’re making frequent service requests: How often have you and I seen each other in the past couple of years? If it’s more than for maintenance or a single repair, this is another sign that your furnace is running inefficiently, leading it to need frequent repairs.
- You feel colder or warmer in certain rooms: Uneven heating is the final sign that your furnace is running inefficiently, wasting fuel, and potentially raising your gas bill. Now, to be clear, uneven heating happens to new furnaces as well, but it’s a far more common sign that an older furnace has become inefficient.
Signs to Tell If Your Inefficient 20-Year-Old Furnace Should Be ReplacedSo, your old friend has gone past just being inefficient to having a full blown break down. It’s okay, mourn for a while, but then realize that your furnace has done its best and served you well. The fact of the matter is, though, that you need to get a new furnace. Here are a few of the most common signs that your 20-year-old furnace needs to be replaced:
- Old age: This one is the simplest. Simply being old (and 20 is definitely old for a furnace) is a clear sign that you will have to replace your furnace soon.
- The burner flame has turned yellow: This is one of the most serious problems an older furnace can have because it could be a sign that your furnace has started to produce carbon monoxide. This is a very dangerous situation, one that should have you calling a trained professional to replace your furnace ASAP.
- The thermostat can’t keep up: Another clear sign that your furnace needs to be replaced is that you can’t get comfortable. No matter where you set the thermostat, you’re always cold in your house. Heck, your furnace may even be blowing cool air. These signs can also apply to some minor issues, but if your furnace is of a certain age, it’s a pretty clear indication it’s time to invest in a new, more efficient model.