propane vs natural gas furnace home heating illustration

You’ve decided on a gas-powered furnace, but have you compared the benefits of natural gas vs. propane gas? Natural gas and propane gas are two standard fuels for space heating, water heating, and cooking. Natural gas and propane gas are not interchangeable; furnaces and other gas appliances are designed to use one or the other.

Natural gas and propane gas are both sourced from fossil fuels and offer many of the same advantages over other types of furnaces. Both gasses burn cleanly and heat quickly. However, natural gas and propane differ in origin and composition, contributing to additional discrepancies in heat output, efficiency, eco-friendliness, safety, and storage.

What is Natural Gas?

Natural gas is a fossil fuel for furnaces, water heaters, and stoves. Underground pipelines deliver natural gas to homes in certain municipalities. Natural gas is colorless, odorless, and tasteless. A chemical odor is added during processing to make gas leaks detectable.

Natural gas is the most common heating fuel in the United States. According to the U.S. Census Bureau, 51% of homes utilized natural gas heating in 2020. It is derived from underground compounds of methane, ethane, butane, propane, and carbon dioxide. Most of the raw natural gas components are removed during processing. Natural gas is 90% methane.

The underground natural gas compounds formed from plant and animal remains millions of years old, buried under layers of sand, silt, and rock. Pressure and heat transformed the remains into coal, oil, and natural gas.

natural gas furnace meter outside of home

What is Propane Gas?

Propane gas, also known as liquefied petroleum gas, LPG, and LP, fuels furnaces, stoves, grills, trailers, and engines. Liquid propane is compressed and stored in tanks. Propane is nontoxic, colorless, and odorless. A chemical odor is added during processing to make gas leaks noticeable.

Propane is a natural gas byproduct extracted during processing to eliminate condensation in natural gas pipelines. Like natural gas, conventional propane is a fossil fuel. Renewable propane, on the other hand, is not a fossil fuel. Renewable propane derives from agricultural waste.

propane tank for furnace heating outside of modern home
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Natural Gas vs Propane: What’s the difference?

Natural gas and propane differ in BTUs, energy efficiency, environmental impact, safety, storage, and transportation.

BTU Comparison

BTU (British thermal unit) is a unit of energy to measure heat output, precisely the amount of energy required to raise the temperature of one pound of water by one degree Fahrenheit. Higher BTUs indicate more heat output.

  • 1 cubic foot of natural gas = 1,030 BTUs
  • 1 cubic foot propane = 2,516 BTUs

According to the comparison above, propane gas produces more heat than natural gas.

Energy Efficiency

Propane furnaces consume less fuel than natural gas furnaces because propane has more than two times the BTUs of natural gas. Therefore, propane is a more energy-efficient fuel. A 100,000 BTU natural gas furnace burns 97 cubic feet of fuel in one hour vs. a propane furnace which burns 40 cubic feet of fuel in one hour.

Environmental Impact

Natural gas and propane are both clean-burning fuels, but natural gas contains methane, a greenhouse gas harmful to the atmosphere. Propane, however, is non-toxic, burns cleaner, and is considered a “green” fuel. Propane is eco-friendly before and after combustion. Neither leaking propane gas nor propane exhaust damages the atmosphere. Renewable propane is even more eco-friendly because it’s derived from sustainable agricultural waste.


Both gases are flammable, but natural gas has a higher flammability rating. Propane tanks are less likely to explode, but if they do, the impact is less because propane lines are not part of a grid system connecting houses. Natural gas dissipates into the air quicker than propane because it's lighter, but leaks in underground pipes are difficult to find and fix.

Storage and Transportation

Underground pipelines supply natural gas to homes, so it’s always available. Propane must be delivered by trucks and stored in tanks.

Propane is more manageable than natural gas to store and transport because it becomes a liquid at -46 degrees Fahrenheit and remains a liquid when held under pressure. Natural gas storage and transportation are more complicated and constitute an explosion risk.

Propane vs Natural Gas Cost

Natural gas cost is measured in cubic feet, and propane gas cost is measured in gallons. Both fuel prices fluctuate. According to the U.S. Energy Information Administration, natural gas prices averaged $7.37 per thousand cubic feet in October of 2022, and propane prices averaged $2.66 per gallon.

Propane prices are historically higher than natural gas, but because propane has higher BTUs than natural gas, less fuel is consumed when heating. So although propane costs more than natural gas, it can be cheaper if less energy is used.

Propane or Natural Gas: Which is better?

There is no clear answer for whether propane or natural gas is better. Each household has to make its determination. Natural gas has a more convenient delivery system, costs less, and you pay for it as you use it. Propane tanks must be regularly filled, and you are charged for the amount of fuel the tank takes. Therefore, natural gas is better if you can access the supply line.

On the other hand, propane is a good option if your home does not have access to natural gas lines. It has high heat output and is efficient, eco-friendly, and safe.

natural gas vs propane comparison illustration

Frequently Asked Questions

Can a propane furnace be converted to natural gas?

Yes, a propane furnace can be converted to natural gas. Converting your furnace requires a few adjustments and a propane conversion kit.

How to tell if my furnace is propane or natural gas?

Check your utility bill to determine if your furnace is propane or gas. Your furnace is natural gas if natural gas is listed on your statement. Your furnace is propane if you have a propane storage tank.

How much does it cost to convert a gas furnace to propane?

According to Home Guide, converting a natural gas furnace to propane costs $275 to $800 if you rent the storage tank and $1,900 to $4,900 if you buy the tank. The total cost includes the conversion kit, the cost of labor, and installing propane gas lines in the furnace.

Additional costs include capping the gas line and removing the piping.

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Adam Gottfried

Adam Gottfried

My wife and I take advantage of our provider’s Summer Fill Program with reduced Propane rates. We pre pay for our winter heating fuel then, and also take advantage of their “auto fill” service in which they keep our tank topped off so we don’t gave to ever worry about running out of propane in the winter. We don’t have to worry about the monthly heat bill either. Very convenient!

mike defelice

mike defelice

You do not discuss the cost of delivery for natural gas. Last month I paid 132 dollars delivery for 34 dollars of natural gas. New York State and Central Hudson is the supplier

Ava M

Ava M

It sure was helpful when you said that what is likely to explode is propane, and its impact is less. My husband and I are interested in finding the right heating fuel for our new house in the south. We want to choose a type of fuel that can give us peace of mind and save us money in the long run, so we will keep your tips in mind.

Taylor Abrams

Taylor Abrams

The statement that propane is a more energy-efficient fuel since propane furnaces utilize less fuel than natural gas furnaces is my favorite portion of your blog. In light of this, I shall look for a dependable propane provider for my heating needs here at home. Your advice is valuable because I’m trying to discover a heating alternative that won’t break the bank each month so thanks, I appreciate this a lot.

Shammy Peterson

Shammy Peterson

The best part of your blog for me is when you said that propane is a more energy-efficient fuel because propane furnaces consume less fuel than natural gas furnaces. With this in mind, I will find a reliable supplier of propane supplier. I want to find a cost-effective heating option to keep everything within the budget on a monthly basis, so your tips are helpful.

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