How Many Watts Does Your Furnace Use? Complete Power Guide

TL;DR

Electric furnaces use 10,000-50,000 watts, while gas and oil furnaces require 400-1,200 watts. The wattage depends on factors such as unit size, efficiency rating (AFUE), age, usage patterns, and home insulation. Power consumption varies by furnace cycles, with most units running about 40 minutes per hour, resulting in about 66% actual wattage use.

What is a Furnace?

In the context of HVAC, the furnace is a heating system that burns gas to produce warm air. Generally, the fuels are gas or propane.

Some key components of a gas burner are:

• Burner
• Heat exchanger
• Blower fan
• Thermostat
• Flue pipe

Electrical Components in a Furnace

The furnace typically relies on gas or propane. For heat generation, the system mainly performs a combustion process. However, the mechanical process involving the combustion and distribution requires some electricity.

Here are some components that require electricity in the furnace:

• Ignition system
• Blower fan
• Thermostat
• Control board
• Safety systems

Factors That Influence Furnace Energy Consumption

Even with the same components, different furnaces can use different energy consumption rate. Things that mostly affect how much a furnace will burn are:

• Size of the Furnace: Larger units consume more power.
• Efficiency Rating (AFUE): More efficient furnaces use less energy.
• Age of the Furnace: Older units tend to use more power than newer, energy-efficient models.
• Usage Patterns: Continuous usage demands more energy than intermittent use (e.g., regions with extreme winters).
• Insulation and Home Size: Poor insulation leads to higher energy use.

How Does a Furnace Work?

A furnace takes in the cold air from the outside environment, heats it, and then releases the air indoor. The different components we have mentioned earlier work together to achieve this goal.

In the simplest terms, here’s how a furnace or gas burner works:

1. The gas burner burns the fuel (gas or propane).
2. The heat burner passes this heat to the heat exchanger.
3. Air passing through the ductwork takes the heat from the heat exchanger.
4. The blower then distributes the air indoors through supply ductwork.

Average Wattage of Different Furnace Types

Different types of furnaces consume different amounts of energy. Here’s the general usage of power in different furnaces:

• Electric Furnace: Between 10,000 to 50,000 watts (most residential electric furnace has around 20,000 watts)
• Gas Furnace: Between 400 to 1,200 watts
• Oil Furnace: Highly dependent on the oil burner wattage. The oil burner’s wattage is usually between 800 to 1,200 watts

Keep in mind that the actual wattage in a system is lower than the stated wattage.

How to Calculate Furnace Power Consumption?

The running wattage depends on the number of cycles (on and off cycle) in an hour.

Factors to keep in mind while calculating the power consumption of a furnace:

• Usually, the furnace has 2-3 complete cycles in an hour.
• Each cycle lasts for 15-20 minutes.
• So, an average of 40 minutes of running time in an hour (66% of the time).

So, if a furnace is stated to be 10,000 watts and runs for an hour, the energy consumed is 6,666 kWh.

How to Reduce Furnace Energy Consumption

The household energy consumption of a US home is twice of a car. And, it’s around 55% of it goes into either heating or cooling. So, reducing your furnace expenses can greatly cut your bills.

Here are some tips to reduce your overall energy consumption of the furnace:

• Depending on where you live, get an annual or bi-annual service.
• Set your thermostat settings 10-15 degrees lower when you leave for the day.
• Try investing in a smart thermostat to set the optimum temperatures automatically.
• Add insulation to exterior walls.
• Check for cracks or gaps in windows, doors, or external vents.
• Replace air filters regularly.
• Upgrade your HVAC system if it’s too old.

Regular maintenance reduces both energy waste and bills over time. And, professionals are equipped to check and tune up your furnace way better than . Consider signing up to a professional plan like The Chill Preventive Maintenance Plan to get the most out of your furnace and HVAC system.

Conclusion

Furnaces mainly rely on gas or propane for heat generation. But they still need electricity to power components like blower fans, ignition systems, and thermostats. Different factors contribute to how much power a furnace will consume.

With proper calculation of energy use and simple energy-saving tips, you can significantly reduce energy waste and lower your utility bills. A well-maintained furnace will provide warmth and help you save money in the long run.