Would you believe that more than half of your home’s energy costs are from your heating and cooling? This is the reason why it’s essential to maintain an energy-efficient HVAC system.

Furnace efficiency standards were last modified to an Annual Fuel Utilization Efficiency (AFUE) rating of 80% in 2015. This rating system calculates how effective your furnace is at natural gas into heat. An AFUE rating of 80% means your furnace loses about 20% of the fuel it uses while creating heat.

In 2022, President Biden revealed new energy-efficiency standards for residential gas furnaces that would greatly decrease emissions, save money and stimulate sustainability.

The updated standards are expected to:

  • Save Americans $1.9 billion annually.
  • Cut carbon emissions by 373 million metric tons and methane emissions by 5.1 million tons over three decades, the equivalent of what 61 million homes emit each year.

Starting in 2029, the proposed rule would require all new gas furnaces to feature AFUE ratings of 95%. This means furnaces would convert nearly 100% of the gas into usable heat.

Considering these guidelines, you might be asking yourself what does that mean for my existing furnace? For the time being, next to nothing, as the proposed rule won't go into effect until 2029 at the earliest and will not affect furnaces that are already in use.

But if you are considering furnace replacement in soon, highly energy-efficient furnaces are already available. Find out how these furnaces can lower your monthly energy bills.

Guide to Condensing Furnaces

How Condensing Furnaces Work

A condensing furnace is a kind of heating system that uses a secondary heat exchanger to trap wasted heat from the furnace's exhaust gases. This limits the amount of energy wasted, improves energy efficiency and lowers greenhouse gas emissions. It also involves less natural gas to create the same amount of heat when comparing one to other types of furnaces.

How Condensing Furnaces Differ from Non-Condensing Furnaces

The biggest difference between a condensing furnace and a non-condensing furnace is that the former uses a secondary heat exchanger to gather any wasted heat from its exhaust gases, while the other does not.

Equipment Lifespan

The life span of a condensing furnace will depend on the brand, model and other factors. Generally speaking, a condensing furnace is likely to last between 10-20 years with proper maintenance and regular service. If your heating system doesn’t have regular furnace maintenance, the equipment may have a significantly shorter life span.

Why Condensing Furnaces Require a Higher Investment

For the most part, condensing furnaces type of system is a lot more efficient than standard, single-speed furnaces, as it only consumes the minimum amount of energy required to heat your home, resulting in more savings on your utility bill.

Many variable-speed furnaces are condensing furnaces, although a handful are available in non-condensing models with lower AFUE ratings. If a manufacturer wants a furnace to be classified as a condensing furnace, it must offer an AFUE rating of 90% or higher.

Do Variable-Speed Furnaces Run Nonstop?

A variable-speed furnace doesn’t need to stay on all the time. Rather, it runs at different speeds depending on the temperature in your home as well as the amount of energy it uses to sustain that temperature.

When sufficient energy is required to maintain your desired temperature level, the furnace will increase to a higher speed in order to keep up with demand. This allows for more efficient heating in your home while also offering quieter operation.

Guide to Two-Stage Furnaces

Two-Stage Furnaces: What They Are and How They Work

A heating system with two settings of operating - high and low - is called a two-stage furnace. During the low stage, the furnace performs at a reduced capacity to help maintain the chosen temperature for your home more efficiently. During the high stage, the furnace will instead run at maximum capacity to satisfy demands for more heat. With a two-stage furnace, you can experience greater energy efficiency and balanced temperatures all across your home.

While two-stage furnaces are highly efficient, not all all models are condensing furnaces.

Does a Two-Stage Furnace Function All the Time?

A two-stage furnace should not run constantly. In the low stage of operation, the furnace runs at reduced capacity in order to retain a planned temperature more efficiently within your home. When a greater demand for energy is needed to sustain the set temperature, the unit switches to its high stage and runs at full capacity. For this reason, two-stage furnaces are able to help reduce energy costs without operating continuously.

Contrasting Two-Stage and Variable-Speed Furnaces

Two-stage furnaces have two stages of functionality, low and high. During the low stage, the furnace performs at reduced capacity as a way to uphold a desired level of comfort within your home. When additional warmth or cooling is desired, the furnace will change over to its high stage and operate at maximum capacity.

Variable-speed furnaces, meanwhile, can operate at a variety of speeds in order to maintain a desired temperature more consistently at home. With more options for temperature settings, you also have more flexibility for heating you home and can enjoy greater savings on energy bills.

Differences Between One- and Two-Stage Furnaces

One-stage furnaces have a single stage of operation and operate either at full power or not at all. As a result, the furnace is always running in order to maintain a desired comfort level at home.

Conversely, two-stage furnaces have two stages of operation, low and high. During the low stage, the furnace runs at [lower|reduced} capacity in order to maintain the desired temperature more efficiently. When additional warmth or cooling is necessary, the furnace will change over to its high stage and operate at peak capacity.

Schedule Your Furnace Installation with Miller Climate Control LLC Today

Making sense of modern furnace technology can be confusing. That’s why Miller Climate Control LLC experts are here to help with a no-obligation, no-pressure estimate for furnace installation. We’ll assess your home, your heating requirements and your budget before helping you find the ideal solution. Get in touch with us at to get started today!