If you have ever plopped a couple of steak or burgers on your gas-powered grill and crossed your fingers that you had enough fuel for just one more cooking session than you have probably pondered our title question: “just how long does propane last?”
Unfortunately, the answer to that question is not always cut and dry. The longevity of propane actually varies depending on a number of factors, including the size and condition of your propane tank and the application for which the gas is being used.
Nonetheless, in the following article we will discuss the question, “how long does propane last” in some detail, so that the next time you decide to grill you can do so with utter confidence.
What You Should Know About Propane
A fossil fuel, propane is a byproduct of the refinement process of both natural gas and petroleum. Under almost all conditions, propane has no color or odor. However, for purposes of commercial storage and transport, propane gas is typically compressed into liquid form and specific odorant agents are added for safety purposes.
So how is propane most commonly used? Propane is used in almost all gas-powered barbecues and camp stoves. Some homes—although not many—even rely on propane for powering things like furnace heaters and water heaters. Propane is also used in campers, trailers and recreational vehicles, usually to power certain appliances and to heat these mobile living units and the water that comes into them.
Regardless if you depend on propane to heat your home or water, provide fuel for your BBQ, light your small camp stove or run the appliances in your RV, having enough fuel available is crucial to escaping the cost and inconvenience associated with running out of the fuel—an eventuality that can really leave you stuck and may even prove dangerous if you rely on propane for heat.
The good news is that the shelf life of propane gas is virtually limitless, provided it is stored correctly and secured in a well-maintained propane tank.
Below we will dig deeper into our title question, “how long does propane last,” explaining the typical lifespan of the gas and providing some tips, trick and strategies for keeping the tank in which your propane is housed in tip-top shape.
How Long Does a BBQ Propane Tank Last?
Just how long does that propane that powers your gas grill last? Given that gas grills are one of the most common applications for propane gas, we’ll address this question right off the bat.
Anyone who grills on a regular or consistent basis understands just how maddening it can be to run out of fuel in the middle of a barbecuing session. Unfortunately, this happens more than you know, largely because the lion-share of gas-powered grills do not have reliable fuel gauges.
Because of this, understanding just how long your propane will last can be the difference in enjoying a well-cooked grilled meal and utter frustration.
The majority of gas-powered grills on the market today utilize the standard 20-pound propane tank. And the cooking time you can typically get from one of these tanks really depends on the size of your barbecue and the number and length of the burners used to dispense the fuel.
On a mid-sized barbecue, with two long burners running lengthwise, a full 20-pound propane tank will typically net you about 18-20 hours of continuous cooking time. However, if you are using a very large BBQ, with longer and a higher number of burners, that continuous cooking time is cut to 10 hours or less.
Grills that also have side burners for heating up things like side dishes may provide you with even less cooking time.
Although there are several complex formulas one could to use to predict how long propane will last—and how much propane gas you have left—for the common consumer calculating these formulas is really not necessary; it is typically easier just to play it by ear.
Once you have used your BBQ grill for a while, odds are you’ll become more familiar with all the inner workings, up to and including calculating how long your propane will last. If you are very fastidious, you can even keep track of the hours you use your grill in some type of log book.
Your best bet, however? If you feel like your propane might be running low, and you want to avoid the frustration of having your grill quit on you in the middle of cooking, take the tank to the nearest service dealer and have it refilled.
How Long Does Propane Last When Using It to Heat Your Home?
Although most furnaces in the United States use natural gas, homes that are in out-of-the-way places like cabins, where access to natural gas is limited or not an option whatsoever, may rely on a propane furnace.
And if you utilize propane to heat your home during a long, brutal winter, it is very critical that you learn how to estimate the burn rates of your propane fuel.
To completely understand how long a propane fuel tank in your home will last, you will need to follow a few easy steps. These include:
Check the BTUH Rating of the Furnace
The first thing you will need to do is check the BTUH rating of your propane furnace. The BTUH rating is a measure of the BTU, or British Thermal Units, a unit of heat that is defined as the amount of heat required to raise the temperature of one pound of water by one-degree Fahrenheit.
One gallon of propane contains 95,000 BTU. So, next you will need to divide that figure by the BTUH rating of your propane furnace. This will determine how long one gallon of fuel will allow your furnace to run at full capacity.
Determine the Tank Capacity
Because the BTUH rating only defines how long “one” gallon of propane fuel will last, you are going to need to do a little more math. And the first step is to determine the capacity of your propane tank.
Most tanks that are used to heat propane furnaces are of the 40-pound variety. And these tanks typically store about 9.5 gallons of actual fuel. If your tank is larger or smaller than 40 pounds, you will need to ask your service dealer how much actual propane is in your tank.
Do the Math
Now that you have divided 95,000 by the BTUH rating of your propane furnace, and determined the tank capacity, you will need to multiply those two figures—the burn rate and the tank capacity—to find out exactly how long the propane gas in one tank will last you through the winter.
Because running out of fuel can be very dangerous in extremely cold climates, you should definitely schedule a propane service company to come out regularly to check and refill your tank. Running out of fuel when the temperature drops below freezing should never be an option.
How Long Does a Propane Tank Last?
Now that you have a better idea regarding how long the propane will last in both a BBQ and a propane furnace, let’s talk about the longevity of an actual propane tank.
According to our sources, “large stationary propane tanks—such as those that feed your propane furnace—must be recertified 10 years after the date of their manufacture, and every five years following that.”
So, what could happen if you fail to get these recertifications? Actually, a propane service or delivery company can refuse to fill your tank if it is not certified.
A similar refusal should also be expected if your propane tank is heavily rusted and in very poor condition. That’s because filling a failing propane tank can be very dangerous, even deadly, considering that most propane sources are both invisible and odorless, yet very flammable.
If you want to keep your propane tank in good working order for as long as humanly possible you will need to schedule regular maintenance of that tank with a propane specialist. These specialists perform a wide variety of services, including visual inspections and leak inspections using specialized equipment.
How to Check if My Propane Level Is Low
Last but not least, let’s discuss how to visually check if your propane tank levels are low. This is not always possible with smaller BBQ tanks, but for large tanks that typically fuel propane furnaces and other appliances the process is usually pretty easy. Here’s how:
- Locate the propane tank. The larger propane tanks that heat homes can either be found above ground or underground. They are typically located at least 10 feet from the structure and away from anything else that could accidentally cause ignition of the gas. Above-ground tanks are easy to spot, but for underground tanks, look for a small dome that is protruding from the ground near your home or cabin.
- Check the float gauge. Unlike the small tanks used to fuel BBQs, the very large propane tanks tend to be equipped with float gauges that are very easy to read. These gauges use a floating element to help you read the amount of fuel left in your tank. This level is clearly marked with a dial showing, in percentages, how much fuel you have left.
Propane tanks should never be filled to more than 80 percent of capacity for safety purposes. Experts say you should refuel large propane tanks when their levels hit about 20 percent of capacity, but you can always refuel earlier to take advantage of low propane costs or sales.