Things to Consider
If fixing the heater core on your car isn’t possible before you get into cold weather, a portable car heater is a viable option. However, there are a few things to keep in mind:
Residential heaters (even portable ones) aren’t always safe for automotive use.Although some propane heaters are safe for indoor use, you should never use them in moving vehicles.A 12V portable car heater requires electricity to run, which may cause issues with a weak alternator or a lot of other accessories.
What it comes down to is that while even the best electric car heater will not replace a broken car heater, that doesn’t mean you have to drive around icy cold.
Residential Heaters as Portable Car Heaters
Since residential space heaters heat relatively large volumes of air, you should be able to use one to heat a car. And while most any space heater will put out enough heat to make you toasty warm in no time, there are two potential problems with this solution.
Residential space heaters aren’t designed for small, confined spaces. They typically come with warnings to keep flammable objects (such as a car’s upholstery) 2 feet, 4 feet, or further away from the front and the back of the unit. Inside a car or truck, that typically isn’t an option. So while you might be perfectly fine if you set up a space heater on the floor of your car, you do so at your own risk. The other issue with using a residential space heater is wattage. You’ll need to install an inverter that puts out enough wattage to run the heater. Even then, you could run into a situation where the alternator can’t keep up with the demand.
There’s lots more to know about using a space heater as an electric car heater.
Portable Propane Heaters
Although some portable propane heaters are relatively safe to use indoors, these heaters come with the inherent risk of either fire or suffocation. Propane heaters that rely on an open flame should never be used in a car because of the danger of fire. Heaters that rely on incomplete combustion carry the risk of carbon monoxide poisoning. Portable propane heaters billed as safe to use indoors typically include a safety valve that triggers if the oxygen level becomes dangerously low. That makes them relatively safe to use indoors, but it isn’t recommended to use one in your car while you’re driving.
Portable 12V Car Heaters
The best, safest alternative to a factory heater is a 12V heater designed for automotive use. However, you’ll typically find that the ones designed to plug into a cigarette lighter won’t put out enough heat. That’s because accessories plugged into the cigarette lighter receptacle can only draw so much amperage (typically 10 or 15 amps) without blowing a fuse. Larger 12V car heaters must be wired directly to the battery (typically with an inline fuse for safety) to draw enough power to put out the heat needed during the cold winter months. As to how well these heaters work is concerned, your mileage is going to vary. They rarely put out as much heat as a factory heater, but you shouldn’t be too disappointed if you temper your expectations. Still, you have to think about how much power the heater is drawing. If the alternator isn’t up to the task, you might be better off saving up the money to fix the problem right.
The Bottom Line: Portable Car Heaters Aren’t True Replacements
While some portable car heater options can get you by, depending on what you expect out of such a device, no portable electric heater will ever replace a factory heating system. If money is an issue to the point where the heater core is expensive to access and replace, there are real car heater replacements that tap into your car or truck’s cooling system. However, both are more expensive to purchase and require some installation work. On the other hand, if all you need to do is take the chill off before or during your drive, a space heater on a timer or a weak 12V heater may get you through the worst of the winter. Just make sure to bundle up first.
