Where you aware that more than one-half of your home’s energy costs are needed for your heating and cooling? That’s why it’s critical to have an energy-efficient HVAC system.

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

In 2022, the U.S. government devised new energy-efficiency standards for residential gas furnaces that would significantly reduce emissions, save money and stimulate sustainability.

These revised standards are estimated to:

  • Save Americans $1.9 billion annually.
  • Reduce 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 yearly.

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

With these facts in mind, you may be asking yourself "what happens to my existing furnace"? As of now, next to nothing, as the proposed rule will not go into effect until 2029 at the earliest and doesn’t affect furnaces that are already in use.

But if you need furnace replacement in soon, highly energy-efficient furnaces are now available. Learn how these furnaces can save you money on your utility 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 capture wasted heat from the furnace's exhaust gases. This decreases the quantity of energy wasted, improves energy efficiency and lowers carbon-monoxide emissions. It also requires less natural gas to generate the same amount of heat when compared to other types of furnaces.

How Condensing Furnaces Differ from Non-Condensing Furnaces

The main difference between a condensing furnace and a non-condensing furnace is that the former uses a secondary heat exchanger to collect 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. In most cases, a condensing furnace will last between 10-20 years with proper maintenance and regular service. If your heating system doesn’t have regular furnace maintenance, the unit may have a significantly shorter life span.

Why Condensing Furnaces Cost More

For the most part, condensing furnaces are more cost most to install than non-condensing furnaces. This is partially for their increased efficiency and the additional components needed to capture any wasted heat from its exhaust gases. However, the bonus energy savings can help offset the price of purchase. So long term, it may be worthwhile investing in a condensing furnace.

Guide to Variable-Speed Furnaces

Variable-Speed Furnaces: What They Are and How They Work

A variable-speed furnace can adjust its fan speed based on the heating needs of your home. It runs at a slower speed until it detects a drop in temperature and then ramps up to produce more heat. This [precise fan is significantly more efficient than traditional furnaces, as it only uses the minimum amount of energy needed 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 All the Time?

A variable-speed furnace doesn’t run 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 reach that temperature.

When sufficient energy is demanded to maintain your preferred temperature level, the furnace will switch to a higher speed to manage the higher demand. Precise fan speeds offer more efficient heating in your home while also providing quieter operation.

Guide to Two-Stage Furnaces

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

A two-stage furnace is a type of heating system that utilizes two different stages of operation — high and low. In the low stage, the furnace performs at a reduced capacity as a way to maintain the chosen temperature for your home more efficiently. During the high stage, the furnace will instead function at peak capacity to meet demands for more heat. With a two-stage furnace, you can maintain improved energy efficiency and comfortable temperatures everywhere in your home.

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

Does a Two-Stage Furnace Operate All the Time?

A two-stage furnace won’t run all the time. In the low stage of operation, the furnace operates at reduced capacity in order to retain a planned temperature more efficiently within your home. When a greater demand for energy is needed to reach the set temperature, the heating system switches to its high stage and operates at full capacity. For this reason, two-stage furnaces are powerful enough to help reduce energy costs without operating around the clock.

Contrasting Two-Stage and Variable-Speed Furnaces

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

Variable-speed furnaces, meanwhile, can operate at multiple speeds in order to uphold a comfortable temperature at home. As such, variable-speed furnaces offer greater savings on your utility bills .

Differences Between One- and Two-Stage Furnaces

One-stage furnaces have a single stage fan speed and operate either at full power or not at all. This translates to higher energy bills because the furnace is always running in order to maintain a desired comfort level at home.

Two-stage furnaces, on the other hand, 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 desired, the furnace will switch to its high stage and operate at full capacity.

Make Your Furnace Installation Appointment with Knoechel Heating Today

Modern furnace technology can be confusing. That’s why Knoechel Heating specialists are here to help with a no-cost, no-pressure estimate for furnace installation. We’ll assess your home, your heating needs and your budget before helping you find the best solution. Get in touch with us at to get started today!