Using Portable Propane Heaters in Cars

Think carefully before going the propane route

Close up of a propane heater.

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Propane heaters are great. They can put out a lot of heat, and they’re extremely portable due to the compact nature of propane cylinders. Even when the fuel runs out, getting the heat back on is a very simple matter of disconnecting the spent cylinder and installing a new one.

The fact that propane heaters are so portable may make them seem like a good replacement for a broken car heater, but there are a few key dangers associated with using them in automotive applications. The main issues that you have to consider are fire hazards and carbon monoxide poisoning, both of which can be fatal if you aren’t careful.

We don't recommend using a propane heater in your car. Propane heaters that are safe for automotive use are usually designed with recreational vehicles in mind.

Radiant Heating vs. Catalytic Heating in Portable Propane Heaters

There are two main types of portable propane heater: radiant and catalytic. Radiant heaters burn propane to create a flame that heats up either a metal tube or a ceramic object. The metal or ceramic object then gives off infrared heat. When other objects absorb that heat, they warm up and also emit infrared heat.

Catalytic heaters, on the other hand, rely on the incomplete combustion of propane and oxygen in the presence of a catalyst, which produces heat.

Since radiant heating utilizes a flame and a hot metal tube or ceramic surface, and catalytic heating involves an extremely hot catalyst, both types of portable propane heaters pose potential fire hazards.

Both types also create carbon monoxide, which creates a chance of carbon monoxide poisoning. According to the US Consumer Product Safety Commission, catalytic heaters also pose a hypoxia risk since the process of incomplete combustion can reduce the amount of oxygen in a small, contained area to dangerously low levels.

Using a Portable Propane Heater in a Car

Due to the associated fire hazards and the risk of carbon monoxide poisoning or hypoxia, a portable propane heater isn’t the best possible type of portable car heater out there.

If you do use one, it’s important to choose one that:

These are the absolute, bare minimum qualities that a portable propane heater should have before you use it in any enclosed area, such as a recreation vehicle, tent, or even a residence.

The Dangers of Carbon Monoxide and Hypoxia

Aside from fire hazards, carbon monoxide poisoning is the largest issue associated with portable propane heaters. This is due to the fact that both radiant and catalytic propane heaters create carbon monoxide as a byproduct of their normal operations. While propane heaters are fairly safe to use in open vehicles like golf carts, they can present problems in closed vehicles like cars and trucks.

Carbon monoxide is dangerous because when you breath it in, it binds with your red blood cells just like oxygen. Unlike oxygen, it can’t be used by the cells in your body. It also becomes “stuck” to red blood cells so that they can’t carry oxygen, which depletes the ability of your blood to carry oxygen until the affected cells are replaced.

If enough of your red blood cells are affected, you can die from carbon monoxide poisoning.

The other issue associated with using a portable propane heater in an enclosed space like a car or a recreational vehicle is hypoxia. This is a condition that occurs whenever someone is unable to get enough oxygen due to low oxygen levels in the surrounding environment.

Since the incomplete combustion of oxygen and propane in a catalytic heater can potentially lead to dangerously low oxygen levels, anyone in that enclosed space may suffer from hypoxia.

If you are only in your vehicle for a short amount of time, it’s unlikely that the carbon monoxide level will rise high enough to pose a danger, and it’s also unlikely that the oxygen level will drop enough to cause an issue.

However, the levels of carbon monoxide and oxygen will depend on factors like the air volume in the vehicle, how well insulated the vehicle is, and how efficient the heater is, so it’s still a good idea to look for alternative heating solutions.

Alternate Portable Car Heaters

Some of the alternatives to a propane car heater include:

  • Electric car heaters: These heaters can be battery-powered, run off AC power, or even run off 12V power from your vehicle. Most of them aren't capable of replacing your car heater.
  • Plug-in car heaters: Plug-in heaters are specifically designed to run off AC power, so these are mostly useful in keeping your car from freezing overnight. They can also make your car more comfortable when you first start driving in the morning.
  • Battery operated heaters: These are truly portable heaters, but they're very weak compared to plug-in heaters.
  • 12V car heaters: These are designed to plug into your vehicle's electrical system. They usually aren't hot enough to replace your car heater, but they can take the edge off.