how much electricity does a gas furnace use

How Much Electricity Does a Gas Furnace Use?

Ian Mutuli
Updated on
Ian Mutuli

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.
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Gas furnaces have long been popular for heating homes due to their efficiency and reliability. These furnaces are a common choice for heating homes, especially during the winter season and in areas with colder climates.

But while gas furnaces primarily use natural gas for heat production, they also require electricity to operate various components. The electricity usage varies depending on the type and model of the furnace, as well as its age. But just how much electricity does a gas furnace use?

How Gas Furnaces Work

Gas furnaces burn gas in a combustion chamber, producing heat. At the same time, a gas furnace blower fan draws in cold air from the return ducts and pushes it over the heat exchangers. In the heat exchangers, the heat is transferred to the air by passing it through the furnace, warming the air.

The warm air is distributed throughout the home via metal tubes, ducts, and vents. This process of distribution ensures that all rooms receive a steady supply of warm air, providing comfort during cold winter months

Gas furnaces run in cycles to maintain a consistent temperature in your home. When the thermostat senses a drop in temperature, it signals the furnace to start the heating cycle. The gas valve opens, allowing natural gas to flow into the combustion chamber, which is ignited by the electronic ignition system. The burners produce a flame that heats the heat exchanger, which, in turn, warms the air.

The blower fan then circulates the heated air throughout the house. Once the desired temperature is reached, the furnace cycles off until the thermostat trigger heating again.

One drawback of gas furnaces is the potential risk of carbon monoxide poisoning. Gas furnaces produce the deadly carbon monoxide as a byproduct of combustion. The toxic gas is typically vented outside through a flue or chimney.

Does a Gas Furnace Need Electricity?

While gas furnaces primarily rely on natural gas as their fuel source, they require electricity to operate certain components. Electric power is necessary to ignite the burners, control the blower fan, and operate the electronic controls. Therefore, even though gas furnaces utilize natural gas for most of their heating process, electricity is still necessary to power gas furnaces effectively. Below are the various gas furnace parts which use electricity to provide warmth and comfort in your home.

Gas furnace

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1. Electric Ignition

One of the primary electrical components of a gas furnace is the electric ignition. Traditionally, gas furnaces used a pilot light that required a constant gas supply to stay glowing hot.

However, modern gas furnaces now use electric ignition systems that remove the need for the pilot light. These electronic ignition systems use electricity to ignite the gas burners, resulting in more efficient and reliable operation.

2. Fan Motor

Another crucial electrical component in a gas furnace is the fan motor. This motor is responsible for circulating the heated air throughout the house. It uses electricity to power the fan blades, ensuring warm air is evenly distributed to every room.

The best part, the technology worked its magic and brought us the variable-speed fan motor. This option allows homeowners to control the fan speed and airflow. As a result, homeowners can optimize comfort and energy efficiency while reducing heating costs.

3. Blower Fan

The furnace blower fan is an integral part of the gas furnace that relies on electricity. This fan helps draw in cool air from the return ducts and push it over the heat exchangers. The heat exchangers then transfer the heat from the burning gas to the air, distributed throughout the house.

Therefore, the blower fan motor ensures constant airflow, aiding in heating. Blower fans help circulate the heated air throughout the home. The furnace blower motor is powered by an electric motor and is responsible for pulling in cool air from the return ducts, passing it over the heat exchanger, and then distributing the warmed air through the supply ducts.

Without the blower fan, the heated air would remain trapped in the furnace, rendering the heating system ineffective.

4. Programmable Thermostat

Lastly, the programmable thermostat is an electrical component that allows homeowners to control and optimize their gas furnace’s operation. You can program these thermostats such that they adjust the temperature based on specific times of the day or week, resulting in energy savings.

By installing a thermostat that uses electricity, homeowners can achieve customized comfort while reducing energy consumption.

5. Additional Features

Some gas furnaces come with additional features like built-in humidifiers or air purifiers. These features may require an additional amount of electricity to operate.

How Much Electricity Does a Gas Furnace Use?

An average household gas furnace can consume anywhere between 300 to 800 watts of electricity while operating. However, it’s essential to note that this consumption can vary based on factors such as furnace size, blower motor type, specific configurations, and additional features.

Generally, a rule of thumb is that a gas furnace will consume around 20-30 watts per square foot of heated space. For example, a 2,000-square-foot home would require an electric consumption of approximately 40,000-60,000 watts.

Electric Connection

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Can a Gas Furnace Run Without Electricity?

So, in the event of a power outage, you may need a power source, such as a generator, to kickstart and run your gas furnace. Additionally, some gas furnaces have battery backup systems that power the essential crucial components.

Energy Efficiency in Gas Furnaces

Gas furnaces are very energy efficient, as they can convert a significant portion of the fuel’s energy into heat. This efficiency is measured using the Annual Fuel Utilization Efficiency (AFUE) rating, which indicates the percentage of fuel converted into usable heat. Modern gas furnaces can have AFUE ratings as high as 98%, making them highly efficient compared to other heating options.

Advancements in technology have led to the development of highly efficient gas furnaces. These modern furnaces are designed to minimize electricity consumption and lower the utility bill while maximizing heat output. The following features contribute to improved energy efficiency:

1. Variable-Speed Blowers

Variable-speed blowers are a notable innovation in modern furnaces. Unlike traditional single-speed blowers, a variable-speed motor can adjust the speed according to the heating requirements, resulting in energy savings and reduced electricity costs.

2. Electronic Ignition Systems

Older models of gas furnaces usually rely on a standing pilot flame that burns continuously and consumes an enormous amount of electricity. However, newer models often feature electronic ignition systems, which are more energy-efficient.

Electric Power

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3. Advanced Heat Exchangers

Another aspect of modern furnaces that enhances energy efficiency is the advanced heat exchanger design. These heat exchangers are built to extract as much heat as possible from the combustion process. So, less energy is required to generate the desired warmth.

4. High-Efficiency Blower Motor

The power consumption of the blower motor can vary depending on the furnace’s size and efficiency rating. A high-efficiency furnace will generally have a variable-speed motor, which consumes less electricity compared to single-speed motors.

5. Control Boards

Gas furnaces have control boards that regulate various functions, such as temperature control and fan operation. These control boards require a small amount of electricity to function properly.

6. Professional Installation and Maintenance

To increase the energy efficiency of your gas furnace, it is essential to have it professionally installed. A skilled technician will help determine how much electricity your house uses and the amount of energy your heating system requires, ensure that the furnace is properly sized for your home, and optimize its performance while minimizing energy waste.

Also, remember that regular maintenance and servicing are also key to keeping your gas furnace operating at its best efficiency. Consult with a professional HVAC technician to ensure the internal parts of your system remains in top condition and continue to provide efficient heating for your home.

Professional Installation and Maintenance.

Gas Furnace vs. Electric Furnace

As far as electricity consumption goes, you cannot compare gas furnaces to electric furnaces. An electrical panel can use up to a staggering 50 kilowatt hours of electricity to run! On the other hand, gas furnaces use electricity to power a few components and will hardly consume more than 800 watts.

Tips for Managing the Electricity Consumption of Gas Furnaces

  • Choose a high-efficiency furnace: High-efficiency furnaces not only save on energy costs but also consume less electricity. Look for furnaces with a high Annual Fuel Utilization Efficiency (AFUE) rating.
  • Regular maintenance: Schedule annual maintenance for your gas furnace to ensure it operates efficiently. A well-maintained furnace will consume less electricity and ensure a lower energy bill.
  • Consider programmable thermostats: Programmable thermostats allow you to set temperature schedules, optimizing energy usage and reducing electricity consumption.
  • Optimize insulation: Properly insulating your home will help retain heat and require less cooling. So, insulation reduces the workload on your furnace and, subsequently, lower electricity consumption.

Tips for Managing the Electricity Consumption of Gas Furnaces

In a Nutshell

In conclusion, while gas furnaces primarily rely on natural gas as their fuel source, they require electricity to power essential components such as the blower fan, electronic ignition system, and controls.

Moreover, understanding the electricity needs of your gas furnace is important for proper maintenance and ensuring efficient operation.

Ian Mutuli

About the author

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.
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