Can a Candle Heat a Room: The Cold Truth

Perhaps you’ve seen the designs for a ‘candle heater,’ that have been going around the web for years. It seems exciting at first to think maybe something so cheap and simple could help keep you warm in an emergency. Fire is hot. Ceramic holds heat well. So I got curious and went digging to see if winter warmth was really that simple. Before you have your gas shut off this winter, perhaps we should have a look at the hard facts behind this wild idea.

Do candles warm a room? The math and science varies by room. Let’s say the room is 10×10 with ok insulation, no windows and a door that seals completely. Under these extremely favorable conditions, the answer is basically no. When you put it under a flowerpot, or three, the answer is still no.

Feel the Burn

Perhaps you’ve tried this and felt the heat. If so then you may be arguing with this assertion. If you put a small candle under a clay pot and sit near it you will feel the heat because it isn’t rising to the ceiling as readily and is more available to you. Any heat you can reach will help warm you, but this is not enough to warm a room. Basically, it’s a trick and one that actually costs more energy and money than other forms of heat.

You’ll see if you look, that the person who is credited with this ‘discovery,’ also sells these little candle heaters. They are fine for finger warming as a novelty. It’s a bit manipulative at worst and shows a lack of basic understanding of science and cost analysis at best.

A great alternative is to purchase a safe battery run indoor heater before an emergency occurs. Check out my recommended heater on Amazon here.

How Hot Will the Candle Get

Simply put, there is more to the question than the actual heat a single candle puts off. If you want to heat a room, you need to know what the heat loss ratio is from outside and how well the insulation works. You’ll need to know about all vents, windows doors and any other heat-loss-openings in the room and whether they can be sealed.

Different styles and sizes of candles will burn differently. Naturally, the wick material affects the burning as does the container. Any candle can burn you, however, beeswax is different from a long burning Crisco survival candle.

An average parafin tealight puts out around 100 BTU. Realistically speaking it will take around 1/5 of that candle to heat a square foot a single degree. So a tealight could heat a five foot square room (think of a pup tent and you’re in the right ballpark) for a short while.

Oxygen Burning Heat

Assuming you achieve a perfect seal, and there’s zero heat loss, then you have an oxygen issue. If you plan to be inside the room and use an oxygen burning fuel source to heat the space, you have a finite time within the space before you and the fire suffocate. It will take quite some time, but in general unventilated fire is a bad plan.

A fire loses about 80% of its heat out of a chimney when you ventilate. What this means is that most non-fire heat sources are far more effective at heating you and your room.

What Can I Burn

If you are determined to burn for heat, then it helps to know what burns easily. Always keep fires safety in mind so you don’t lose your shelter or your life while trying to survive.

  • Wood, Coal and Other Organic Matter: Things like wood, leaves and even cotton will burn. Please be careful as some woods and many things which are chemically treated may be toxic.
  • Candles- Paraffin, Gel, and Beeswax: Candles and even regular lumps of wax will burn. They are not efficient energy sources, but they’ll keep your fingers from freezing in a pinch.
  • Fats- Lard, Oils, and Crisco: Most fats require a wick of some sort in order to burn. A Crisco Candle is another of those not-quite-as-it-seems internet designs. Crisco burns just fine, but any fire in a cardboard tube is a bad plan.
  • Alcohol and Kerosene: You will need a lamp to burn these safely and efficiently.

Non-Oxygen Burning Heat Options

So, if a fire is wasteful then what options exist for staying warm in an emergency? Well, first, know that inefficient isn’t necessarily bad if it keeps you alive. If you need to warm your fingers over a tealight to stave off frostbite then do it. The fact that it would take a large number of candles to heat an entire room, even for a short while, does not mean you should avoid doing what you need to in a tough situation.

Fashion for Survival

It’s best to start with how you dress. Synthetics are a fine way to retain heat. Unfortunately, in a world or society ending situation these may cease to be an option. A great rule of thumb is that if it works for animals it can work for you. Wool, fur and down (feather stuffed) options are best. Nature has great designs if you look around for them.

If you cannot get your hands on any of these things go for layers. Between the layers of fabric, you’ll want to stuff crinkled paper or leaves. Make sure you don’t choose any poisonous plants to create your insulation. If you have access to it you can use extra fabric or even aluminum foil.

The more layers there are between you and the cold, the slower you will use up the heat you have. If you can keep enough insulation, it will save your life. This applies to living spaces as well as bodies.

Mongol warriors used rancid fat to protect their skin from the freezing temperatures of their homeland. Chapstick or Vaseline might serve the same purpose in an extreme situation, though it seems likely that actual animal fat would work better. Smelling bad, or feeling weird should never stop you from taking necessary steps to preserve your life or those you love.

Alternative Energy

If you are fortunate enough to have a source of electricity, be it a generator or solar panels, then you can run non-burning heat sources. Small energy efficient electric space heaters will do a fabulous job. Old fashioned radiators work as well.

A unique option might be to use a high-efficiency rocket stove to heat water in copper pipes as part of a radiant floor or wall heating system. These use less fuel to accomplish more and are fairly economical and easy to DIY.

Assuming you have sunshine, you can also opt for the ambient solar heater. You’ll need a small solar fan to move air in this case, but otherwise, it’s built of non-moving parts. A solar heater can be put together with some wood, clear plastic, soda cans, black paint, and tubing. It attaches to a window and creates a serious heat source as long as the sun shines.

If You’re Caught Outside

Create your own ‘room’. Basic shelter making is absolutely essential as a survival skill. There is no reason at all to avoid learning to make basic lean-to’s and other simple shelter. It is always easier to retain heat in an enclosed space.

Having a good ‘space blanket,’ on hand for when the SHTF. These incredibly lightweight thermal blankets help reflect and retain your body heat so that you aren’t losing as much.

If necessary, when you’re caught outdoors, you can bury yourself in leaves or pine needles, as long as you keep your body off the ground, but this method is more dangerous.

Don’t Burn Out

When you get cold, your body burns energy. Essentially you use yourself for a heat source. In order for this to work efficiently you need to stay in good health. Exercising regularly, especially cardio, helps keep your body functioning. Make sure you are eating properly so you have the nutrients and fat you need. Also, don’t forget to stay hydrated.

Final Thoughts

With no other available options, always do what you can. If you’re caught in a car in a blizzard this trick may help save your life, at least for a short while. However, there are simply better ways to handle your survival needs. A candle is better for romantic lighting, or at worst heating a very small amount of food. You can certainly keep your fingers from freezing, but for serious survival planning, you’ll want to try almost anything else.

It is best to plan ahead and get other sources of heat that does not run on electricity and can be used indoors. One such heater that I recommend can be found here on Amazon.

Additional Questions

Are there ways to keep warm without heaters? In addition to the ideas above, exercise will help to warm you and skin to skin contact is excellent for transferring heat. Anything involving friction creates heat. Organic decomposition also creates a little bit of heat, so creating a small sleeping space above a compost bin will help keep you warm, though not comfortable. Also, decomposition smells bad.

What else can I do to help heat a home without electricity? Close up any spaces you don’t need to use. Block off the gaps around doors and windows. Use the sunlight you have, plastic shower curtains over existing windows will let in sun without letting so much heat escape. Use rugs and floor covering everywhere. You can use the same principal on the walls, with rugs, tarps or tapestries.

What did people do before heaters and fire? Well, you’d be talking about prehistory if you want to look that far back. Not a whole lot is known about that era. It seems likely that huddling together in caves and wearing animal skins would be about the extent of it. It’s also possible that early humans had more efficient bodies than modern mankind.

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