HVAC technician performing furnace service

Did you know that more than 50 percent of your home’s energy costs are from your heating and cooling? This is why it’s essential to maintain 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 natural gas into heat. An AFUE rating of 80% means your furnace will waste about 20% of the fuel it uses while producing heat.

In 2022, the Biden Administration recommended new energy-efficiency standards for residential gas furnaces that would significantly lower emissions, save consumers money and encourage sustainability.

The updated standards are anticipated to:

  • Save Americans $1.9 billion annually.
  • Reduce carbon emissions by 373 million metric tons and methane emissions by 5.1 million tons over the next 25 - 30 years, the equivalent of what 61 million homes emit yearly.

Starting in 2029, the updated 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.

So what does all of this mean for your existing furnace in 2023? As of now, not much, as the proposed rule won't 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 already available. Find out how these furnaces can help you save on energy bills now.

Guide to Condensing Furnaces

How Condensing Furnaces Work

A condensing furnace is a style of heating system that uses a secondary heat exchanger to collect wasted heat from the furnace's exhaust gases. This decreases the extent of energy wasted, enhances energy efficiency and lowers carbon-monoxide emissions. It also demands less natural gas to generate the same volume of heat in comparison 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.

How Long Condensing Furnaces Last

The life span of a condensing furnace will depend on the brand, model and other factors. Usually, a condensing furnace will last between 10-20 years with appropriate maintenance and regular service. If your heating system doesn’t have regular furnace maintenance, the unit may not last as long.

Why Condensing Furnaces Require a Higher Investment

Usually, condensing furnaces are more expensive than non-condensing furnaces. This is due to their increased efficiency and the extra features necessary to capture any wasted heat from its exhaust gases. However, the added energy savings can often offset the cost of purchase. So in the long run, it may be worth investing in a condensing furnace.

Guide to Variable-Speed Furnaces

Variable-Speed Furnaces: What You Need to Know

A variable-speed furnace can more precisely alter its fan speed to better meet the heating needs of your home. It starts at a slower speed until it notices a drop in temperature and then speeds up to generate more heat. This [precise fan is significantly more efficient than traditional furnaces, as it only utilizes the minimum amount of energy necessary to heat your home, saving you money in the long run.

Most variable-speed furnaces are condensing furnaces, although some 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. Instead, it runs at different speeds depending on the temperature in your home as well as the amount of energy it uses to maintain that temperature.

When sufficient energy is demanded to maintain your preferred temperature level, the furnace will switch to a higher speed in order to keep up with demand. This allows for 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

As the name suggests, a furnace with two levels of operating (high or low) is called a two-stage furnace. During the low stage, the furnace performs at a reduced capacity as a way to maintain the chosen temperature at your home more efficiently. During the high stage, the furnace will instead run at maximum capacity to meet demands for more heat. With a two-stage furnace, you can enjoy greater energy efficiency and stable temperatures throughout your home.

While two-stage furnaces are extremely efficient, not all all types are condensing furnaces.

Does a Two-Stage Furnace Run All the Time?

A two-stage furnace does not stay on indefinitely. In the low stage of operation, the furnace performs at limited capacity in order to maintain a desired temperature more efficiently within your home. When a greater demand for energy is needed to sustain the set temperature, the heating system will switch to its high stage and runs at full capacity. As such, two-stage furnaces are proven to help reduce energy costs without operating continuously.

Differences Between 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 in order to maintain a desired level of comfort within your home. When a greater demand for warmth or cooling is necessary, the furnace will switch to its high stage and operate at full capacity.

Variable-speed furnaces, meanwhile, can work 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 of operation and operate either at full power or not at all. This means that the furnace runs constantly in order to maintain a desired comfort level within your home.

Two-stage furnaces, by comparison, 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 more warmth or cooling is needed, the furnace will change over to its high stage and operate at full capacity.

Schedule Your Furnace Installation with Bishop’s HVAC Today

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