I hear that more and more folks are unexpectedly living in their cars these days, and of course, there is always the chance of getting stranded. I hope neither one happens to you or me. But anyway - in the interests of preparedness - I came across the plans for an emergency car heater, using a one-pound coffee can at:

http://www.equipped.org/coffe_can_survival_heater.pdf

On a trial run I was a little alarmed at the amount of open flame produced. This could be a safety issue in smaller cars. I am thinking that inverting a three-pound, vented coffee can over top of the burner would shield the open flame while also releasing and radiating heat.

Has anyone tried anything like this? Also I am curious as to why the instructions call specifically for seventy percent isopropyl and warn against using "anything stronger". Methanol (gas-line "Heet") seems to burn cleaner. Does it present a CO hazard?

Not sure about harmful, but the alcohol stoves on some of the older sailboats I've been on put out an odor and fumes that could make the hardiest sailor sea-sick.

I would not want the same thing inside a car.

I'm guessing that when the alcohol burns off, the 30% water left behind will prevent the paper from starting to burn.

You could always use 91% Isopropyl alcohol or better yet, Everclear 191proof. But they do burn a lot hotter, maybe too hot for a coffee can heater for use in an enclosed space. I'd stay away from Methanol as its much less human friendly than rubbing alcohol or food grade ethanol. Lots of informed ETSers can point out exactly why that is due to its chemistry but I'm not one of them. Rubbing alcohol and Everclear are also 'multiple use' fuels.

Instead of turning a 3 pound can over the burner, how about setting the burner in the 3 gallon popcorn can they suggest carring it in?

David Enoch

Since it has an open flame -- consuming oxygen, I would assume a it presents a huge CO hazard.

You don’t need a heater / burner that big to heat up an auto. A small alcohol backpacking stove (there are about 50 free plans on the net) that can be made for free will heat up a full sized van fine.

I would use denatured alcohol for the fuel.

As far as the CO output, open the window a bit.

ANY burning of ANY sort produces TOXIC CO2 --never use inside an enclosed space.

DO NOT use charcoal or a propane grill (for example) inside a tent or building.

...Gets down off soapbox...

I am very dubious about the no carbon monoxide bit.

Rule is that you always open a window 1-2" on the down wind side of the vehicle.

Also, I think that I would prefer a candle heater + sleeping bag & blankets etc. You should also assess if staying in the vehicle is a good idea. You might be bettter off and warmer in a snow hole.