Here in Metuchen, NJ, every homeowner knows how important a reliable heating system is in the winter. They also know how expensive it can be to keep your home warm when temperatures drop. So, furnace energy efficiency is already a topic that gets plenty of attention here. However, that doesn’t stop the average homeowner from balking when they see the price difference between a furnace that’s 80% efficient and one that’s 90% efficient or more. Some believe that they’re simply paying a premium to save a bit on their energy bills. But the reality is that there are some significant differences between furnaces at those two efficiency levels. Here’s a detailed explanation of what those differences are and why high-efficiency furnaces are worth every penny.

Understanding Mandatory Efficiency Standards

If you’ve ever gone shopping for a furnace in the past, you’ve likely run across a rating system called AFUE. It stands for annual fuel utilization efficiency, and it’s the standard measure of a furnace’s operating efficiency here in the U.S. The thing is, it’s completely interchangeable with the efficiency percentages mentioned above. So, a furnace with an AFUE of 80 is 80% efficient, and one with an AFUE is 90% efficient, and so on. But what you may not know is that HVAC companies like Sam's Air Control can only legally sell furnaces that meet specific minimum efficiency standards.

According to the regulations set by the U.S. Department of Energy, homeowners in New Jersey can only purchase gas furnaces that operate at a minimum of 81% efficiency. However, there are plenty of gas furnaces on the market that operate at 90% efficiency or above. What you won’t find, though, are many furnaces with efficiency ratings between those two. The reason for that is the fact that the kinds of mechanical and design changes required to raise a furnace’s efficiency much beyond 81% push both their price much higher and their efficiency beyond 90% by default.

How 80% Efficient Gas Furnaces Work

The average gas furnace that operates at 80% efficiency relies on a single-speed blower and a burner that only runs at a single output level. When your thermostat calls for heat, the burner ignites, and the gas burns using air drawn from the furnace’s surroundings. This is called an open combustion process, and it is one of the main things that separates an 80% efficient furnace from one with an efficiency of 90% or above.

The hot gasses created by the combustion process pass through a heat exchanger, and the blower fan pushes air from your home across its fins, warming it up. However, the heat transfer created by that process isn’t very efficient. As a result, around 20% of the heat ends up escaping your home via the furnace’s flue. The heat exchanger technology in use in an 80% efficient is already as advanced as possible, which means manufacturers can’t squeeze any more efficiency out of such open-combustion designs.

How 90% Efficient Gas Furnaces Work

On the other hand, gas furnaces that operate at 90% efficiency or above contain some additional technology to capture more of the heat generated by the combustion process. For one thing, many have multi-speed blowers and burners that can run at multiple output levels. This allows them to use only as much fuel as necessary to meet your home’s heat demand, which helps minimize waste.

Such furnaces also use a closed combustion process, which uses a sealed combustion chamber that doesn’t allow heat to escape and relies on air drawn from outside your home. That eliminates one of the wasteful parts of the process you’d find in a lower-efficiency furnace. They also have a secondary heat exchanger that captures additional leftover heat from the combustion gasses before they vent out of your home. As a result, there’s even less waste. That’s also why the flue for a 90% efficiency furnace is often made of PVC instead of metal since the final gas output leaves your home at a far lower temperature. Plus, you’ll find that 90% efficient furnaces also require a condensate drain pipe because they cool the exhaust gasses to the point of condensation.

It’s also worth pointing out that 90% efficient gas furnaces can make your home more comfortable than their less-efficient cousins. Since they don’t need to run at full output all of the time, you should experience more consistent indoor temperatures and fewer hot and cold spots in your home. With such a system, you get exactly the amount of heat you need when and where you need it at all times.

Price Difference Between an 80% and a 90% Efficient Furnace

On average, you can expect to pay between $1,000 and $1,200 more for a 90% efficiency furnace compared to an 80% efficient one. However, the actual price difference can vary considerably depending on your home’s specific heating needs. The good news, however, is that both options should last between 15 and 20 years if you keep them maintained properly.

As a result, a 90% efficiency furnace will pay back its premium within seven years, on average. Once that happens, the remaining eight to 13 years of energy savings go straight back into your pocket. So, over its lifetime, a 90% efficient furnace is more than worth spending a little more upfront. When you consider the added comfort you’d get from one, that’s even more apparent.

You should also know that there are federal tax credits available if you choose to purchase a furnace that’s 97% efficient or more. Under the Inflation Reduction Act, you can claim a credit worth up to 30% of the cost of installing such a furnace, up to a $600 maximum. The only restriction is that the furnace you choose must be ENERGY STAR certified, which the vast majority of high-efficiency furnaces are in any case.

Your Local Gas Furnace Experts

Whichever efficiency level furnace you ultimately choose, you can count on Sam's Air Control to install it for you. We’ve served homes and businesses in and around Metuchen since 2014. We offer expert HVAC installation, maintenance, and repair services. That includes boilers, geothermal systems, and ductless HVAC, too. We also offer indoor air quality solutions and ductwork services, too. And our team of fully licensed HVAC technicians has the tools, knowledge, and experience to provide flawless services on HVAC systems of all makes and models. Our long list of five-star reviews from satisfied customers like you can attest to that. We even offer financing on approved credit to help you pay for the new furnace you need. We also work with the energy savings programs of all of the local utility companies to help you save even more! So, when you’re ready for a new furnace for your Metuchen home, call the experts at Sam's Air Control right away.

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