Choosing a gas furnace isn’t always the easiest decision to make. They all look about the same from the outside and figuring out what the specs mean can be pretty confusing. The bottom line is that you want a gas furnace to:
- Be efficient – so you are not paying high gas bills all winter
- Be reliable – It should work when you need it to work.
- Be quiet – the less noise, the better.
- Be installed correctly and at a fair price.
Efficiency – the easiest to get right.
All new furnaces are pretty efficient by historical standards. In 1987, the first federal standards were put in place for gas furnaces. By 1992, gas furnaces had to achieve 78% Annual Fuel Utilization Efficiency (AFUE). Essentially, this means that 78% of fuel used is turned into heat in your home. Before this rule, furnace efficiency was in a broad range between 56% to 70% AFUE. The standard caused a shift in manufacturing processes and led to gas furnaces that no longer had standing pilot lights. More than 30 years later, you are unlikely to have a furnace less efficient than 78% AFUE in your house. If you do, you are overdue for a new system.
Current standards slightly increased the minimum AFUE rating of new furnaces to 80%, which quietly went into effect in 2015. This impacted almost nobody, as by that time there was not a single manufacturer that we know of still making gas furnaces with a below 80% AFUE. The bottom line is even if you buy the least expensive gas furnace available, you are going to get pretty good efficiency for the short, less demanding winters we have here in the Charlotte area.
In 2015, the federal government calculated the energy savings of three levels of gas furnaces over their 20 year expected lifetimes. A top-of-the-line 97.5% AFUE furnace saved you less than $100/year on your gas bill each winter. Compared to the higher initial cost of an Energy Star or super-high efficiency model, picking a higher efficiency model won’t save you money unless natural gas prices start climbing rapidly. However, the government currently forecasts natural gas prices to rise less than 1% through 2050.
Reliability – Trane is known for this.
Reliability is important in selecting a gas furnace. Most of the major brands are fairly reliable. We install Trane systems, in large part, because they have proven to be very reliable. We’ve installed other brands in the past and experienced some issues, which led us to Trane. Trane has been named America’s Most Trusted HVAC Brand for 4 straight years, receives great marks from places like Consumer Reports and online review sites. Plus there are these videos:
We’ve always considered this more of a problem with air conditioners, but quite a few people ask about how loud a new furnace will be. Some of the noise considerations have to do with the placement of the unit and how the ductwork functions. Some ductwork changes, like larger air returns can help with noise in certain situations. However, furnaces do vary in how loud they operate.
Here’s where investing in something better than a base model 80% AFUE furnace will make a difference. The first step up is to a 2-stage model. Your standard 1-stage model has only one burn rate and produces full heat all the time. A 2-stage model has a high and low burner setting. This helps regulate heat in the home and prevents the larger temperature swings you get with a single stage unit. And it also helps with noise. When the furnace is running on the lower burner setting, it should be much quieter than when it it is running on the high heat stage (essentially your only setting with a single stage furnace).
The next step up is going to a variable speed blower with a 2-stage furnace…but still at an 80% AFUE. Variable speed blowers change the rate of air flow in the home based on the temperature. So you might be running at a lower blower speed for 60-80% of the time. Think about a hair dryer. Most have 2 or 3 speeds and you can notice the difference in noise based on how fast the fan is running. The same is true for a variable speed furnace blower. Non-variable speed furnace blowers are either on high or off. Variable speed blowers will be much quieter most of the time, unless peak heat production is needed. Since this is generally the air handler for your air conditioning in a standard system in the Carolinas, you may want to consider the decision to step up to variable speed in context to the summer as well.
Finally, if you really want the quietest operation, you have to step up to a high efficiency furnace. To gain that higher efficiency, furnaces with 90 AFUE or greater have sealed combustion chambers. It is done for efficiency reasons, but the side effect is that it makes the furnace much quieter.
Trane’s quietest gas furnace is the S9V2-VS. It is 97% AFUE. It uses a variable speed Vortica II blower and a variable speed draft inducer to keep the air handler sounds as quiet as possible. You’ll appreciate that in both the winter and summer.
Proper Installation at a Fair Price
Installation is key to furnace performance. Unfortunately, there is a lot of poor quality installation out there. One federal government estimate puts high quality installation at only 20%. And that isn’t surprising considering the findings of some other studies. A 2016 study of California HVAC contractors found only 75% had formal installation guidelines and standards. There is a quarter of installations that are likely to be done poorly because of lack of training. At Panther, we believe in a well-trained work force and provide high-quality installations. The 66% of HVAC contractors who say that customers won’t pay a fair price for proper installation are the ones that are always having to run gimmicks to bring in new customers. We believe in providing quality installations of quality HVAC equipment at a fair price, so our customers keep coming back for repairs and replacements years later.