How Many Gallons of Propane Does a Furnace Use?

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Are you one of the thousands of people who turn on their propane furnaces when the weather turns chilly and leave it to do the work?  If that's the case, it could be a good idea to think about how much fuel you'll need not only to keep your home comfortable but also to keep your tank full.  We've researched how many gallons of fuel a propane furnace uses to help you estimate your annual consumption. 

Furnaces use most of your propane fuel among all your propane appliances. A 100,000 BTU propane gas furnace, which is the average fuel rate for residential houses, uses roughly 1 gallon per hour. Annually, it is estimated to be 500–1,200 gallons.

Certainly, the amount of propane used by your furnace depends on several factors, such as your house efficiency, the time of year, and other variables. Let’s dig further and learn more if you want to know how much propane you use on an average day to predict and manage your propane costs so that you will not let your money go to waste.

A home high efficiency furnace with a residential gas water heater & humidifier - How Many Gallons of Propane Does a Furnace Use

How much propane does it take to heat a house a day?

A home high efficiency furnace, boiler water heater and humidifier.

If you don’t have a furnace yet and you’re just planning to buy one, it is important to first know the size of your furnace and later on determine its propane use to heat your house for a day.

In most northern regions with cold winters, a home furnace will need to generate between 40 and 45 BTUs per square foot of heat. Based on the square footage of your home, you may get a general estimate of the furnace size you'll need. Let’s say you have a 2,200-square-foot house. This means you need roughly 90,000 BTU to heat your home. 

Because a typical furnace has a 90% efficiency rating, you will need a higher furnace rating than the calculated heat requirement. In this case, a 100,000 BTU propane furnace is desirable for your home.

Now, because you are unlikely to use your propane furnace 24 hours a day, every day, the calculation below is for using it depending on your desired hours of use per day. Furnaces with BTU ratings ranging from 40,000 to more than 200,000 BTU are also available, owing to a range of household heating needs. The majority of furnaces are in the 80,000 to 100,000 BTU range.

Don’t want to run through the arithmetic? Skip to the end of the paragraph to see the average!

Otherwise, here’s an example:

  • 100,000 BTU/hours (the furnace capacity) x 91,547 BTU/gallon of propane (propane’s thermal energy) = 1.09 gallons per hour
  • 1.09 gallons per hour x 2 hours per day = 2.18 gallons per day

Generally, household furnaces run 2–6 hours a day during the colder months, which means 2–6 gallons of propane are needed to burn per day if an average 100,000 BTU propane gas furnace is used.

What is the average price for a gallon of propane?

A home high energy efficient furnace in a basement

According to the published weekly survey of residential propane prices per gallon as of 2021-2022 conducted by the US Energy Information Administration, the average price is 2.983 dollars. Numbers show that the propane price per gallon today is on average 6.88% higher than it was at this time last year.

Because weekly propane prices are only collected during the heating season (from October to March), the US Energy Information Administration has not published data on today's propane price per gallon in all US states. That means the next update of data will return on October 5th, 2022.

Do you want to know the prices for each state? Simply click here to see the US Energy Information Administration's full publication for heating oil and propane residential and wholesale prices.

How much does it cost a month to heat with propane?

New Steam heat furnace fueled with natural gas.

Now that we’ve got our data, let’s do the math and calculate your total propane furnace heating costs. Don’t worry, it’s easy! Just follow these two steps.

First, determine how many days per month you use your furnace. For this computation, let’s say 30 days for the whole month. Then, multiply the number of days by the amount of propane you used per day. Let’s take the example above.

  • Example: 30 days per month x 2.18 gallons per day = 65.4 gallons per month

Next, multiply the number of gallons per month by the current price of propane:

  • $2.983 per gallon x 65.4 gallons per month = $195.1 per month

Not too bad! Especially when you consider how environmentally friendly propane as compared to most other fuel sources.

The result of your computation will vary based on the number of hours and days of your usage, the rating capacity of your furnace, and the market price of propane.

How often do you have to fill a propane tank for a house?

A home high energy efficient furnace in a basement

Unfortunately, there’s no one-size-fits-all answer to this question, but the average homeowner is expected to have their tank refilled at least twice a year. The rate at which you use your propane varies on the heating requirements of your home, the number of people living in it, not only your furnace but other appliances you have that also use propane fuel, and the size of your tank.

When these considerations are taken into account, it is difficult to determine the exact lifespan of a 500-gallon propane tank, which is the most typical size for residential propane use. However, depending on the time of year and usage, most 500-gallon tanks can keep the average home operating for a month to a few months.

In Conclusion

Running out of propane causes an inconvenience throughout the winter season. You will not be able to power the appliances that use this fuel. So, it is best to regularly check your tank gauge. Then, get in touch with your propane provider and schedule a refill when your tank drops to 30% full. 

Don’t wait for your tank to hit below 5%, because it will take time for your provider to run additional tests to check for leaks. This is a legally compulsory measure that will also cost additional fees.

For additional reading, check out our related posts: 

How Hot Can A Propane Furnace Get?

How Often Should A Propane Furnace Be Serviced?

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