Instructables
Picture of Tea Candle and Ceramic Flower Pot

There's been a slight debate on whether this actually works or not. Whether it's convection or radiation, etc. I believe it's radiating the heat which isn't as effective as if it was convecting it. The original designs I found online has a hole at the very top which I guess allowed more convecting. I like mine because it's simply a little cleaner and easy on the eye. It gives off a little heat and is good for your desk. I keep mine directly next to my keyboard and it feels nice while I'm on Instructables!

Check out my new craft website AnthCraft.com and follow me on Facebook. I plan to keep the awesome Instructables/tutorials coming!

 
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Step 1: What You Will Need

Picture of What You Will Need
  • 1 - Medium ceramic flower pot. Mine is 6"
  • 1 - Small ceramic flower pot. Mine is 4"
  • 1 - Ceramic plate (usually comes with pot, mine is 6")
  • Tea candles (100 for $9.10 here: Amazon.com)
  • 2 - 1/4" x 5" hex bolts (there's a mistake in the picture, both bolts should be fully threaded.
  • 1 - 1/4" coupler bolt
  • 2 - 1/2" nuts
  • 3 - 1/4" nuts
  • 3 - 5/16" x 1-1/2" hex bolts (not shown)
  • 5 - small washers
  • 5 - big washers
  • Drill press/drill
  • Needle nose pliers
  • Adjustable wrench
  • Lighter


Note: If you have big washers with a small 1/4" hole in them, you can use 5 washers total instead of 10. Also, the two large 1/2" nuts are simply spacers. If you want you can use a small 1-1/2" section of a small pipe, or anything that comes to mind. You will see what I'm talking about in step 4.

kingofeye1 month ago

this would be such an inneficient method to make this heater,..check this instead http://www.instructables.com/id/Cheapest-Heater-In...

nmakarowski3 months ago

For any of those coming to this. Don't bother with it. This is completely ineffective as a heater for a number of reasons.

Candles, Regardless of whats above them cannot put out any more heat than they have energy trapped in the wax, and in paraffin candles that amount of energy is very small, about 35 Watts of heat per hour. To put this into perspective, it would take about 43 candles to compare to a 1500w electric heater, and these candles cost about 10$ per 100, and last only about 4-5 hours. This means about $4.30 is needed every 4-5 hours to heat a room effectively. Not to mention the dangers you have to face with 43 lit candles in a room, or the potential oxygen depletion or carbon monoxide risks you're facing. This is in addition to the having to need a place to put 11(4 candle) or 14(3 candle) heaters around the room/house.

Compare this to that 1500W Heater, some of which can be found for as low as 150$, can heat up an entire 1500-1750 Sq ft house/apartment. For whatever the cost of your electricity is in your area. Mine is about 14 cents an hour, so it's $0.14x1.5kw(1500w), or about 21 cents an hour, if it's on full blast all the time(which it won't be, they only turn on when needed).

A 500W-750W heater can be found for quite a bit cheaper anywhere from 25-75$, which won't offer the same heating power, but it can heat up a decent sized room and keep it at temperature quite easily. These are even cheaper to run, and might just suit your needs better. For me it would cost about 7 cents an hour for the 500W heater, and 11 cents an hour for the 750W.

Even if you're living in an area with electricity prices as high as 30, or even 40 cents an hour it's going to be far cheaper to run an electric heater compared to a Tealight heater. If an Electric heater is completely out of the question, then you should look into a Kerosene Heater. Which is liquid fuel heater, and the fuel can be bought in large quantities. It still poses many risks, Fire, Air(it's exhaust is normally vented indoors), but if used safely and properly it offers little to no risk. This is great for area's without electricity. This type of heater is used almost exclusively in Japan in the winter time over there, so it can't be THAT dangerous. Just don't misuse it.

There are other options, but also depend solely on where you live. A Rocket/Jet Stove is a wood burning stove that could be vented outside. It heats up to incredible temperatures pretty much vaporizing wood(small twigs in most cases). The smoke stack/chimney/exhaust w/e you call it, gets incredibly hot because of this. It allows you to heat rooms(with a small unit), Entire houses, with a much larger unit. And you can even use them to heat water by wrapping copper pipe around chimney. This is actually an incredibly efficient way to heat houses and water, though it requires a proper design, and a proper place to put it.

The only reason I took the time to write this is because I would prefer to inform people before they decide whether or not to make something like this. I'm not telling you NOT to make one, I'm just telling you that there are other, way more efficient and cost effective means of heating a house/room/garages. To be quite honest with you. This Tealight heater at best, would be able to heat up a small bathroom. Even then, the Terracotta pots don't offer much of anything except for a small amount of heat radiated off. The rest of the heat will still rise, so it's cheaper and easier to just burn the candles by themselves.

Costarus8 months ago

The amount of heat that allocates candle, remains unchanged. And similar devices, alas, a mindless waste of money. Candles are so small, that are well-suited for themselves. Air convection is excellent. 1 candle has a thermal capacity of about 30 to 40 Watts. But they cannot be put close to each other. They overheat and lights directly paraffin, and not the wick. The flame is very strong, it may be a fire. For burning low in oxygen and strong smoke. I tried to do a good microwave on paraffin. But it is difficult. Need a boost and constant control. (computer translation)

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boter20998 months ago

Awesome Ible'. Well documented and well written.

However - I'd like to point out, what you have designed is a heat exchanger but what you have built is a radiator.

In theory the way this should work is that the "sealed" smaller pot is meant to catch the heat, and warm up. This heat warms the air trapped between the small and bigger pot. As heat rises the warmed air is meant to escape the hole in the end of the pot. This in turn draws cooler air up from the bottom, thus cycling all of the air in the room past the heating element.

However with the hole sealed. The two pots simply warm up and radiate out the heat into the room. Convection is more efficient than radiation.

Might I suggest redesigning your method of attaching the big pot? Possiblly add bolt feet standoffs like on the tray? so that the main hole is left open to allow for better circularion?

Paravival (author)  boter20998 months ago

Very informative. Thanks for the post! I'm going to re-design this and try and go for more of a convection than radiation.

So, I just want to make sure I'm on the same page. You're thinking...Keep the main central bolt, but end it at the bottom of the small pot, and instead of it going all the way to the bottom of the big pot, use three bolts (like legs of plate) and have that be the method of fixing the pots together. This would allow the big pots hole to be open still. Then the heat gets trapped in the small pot, heats up and spill out into the big pot and comes out of the hole up top??

Do you think If I just drilled holes on the top (bottom of big pot around central bolt that's currently there), it would work??

Look forward to hearing what you think.

Thanks,

Anthony

artistajg8 months ago
You got this all wrong. The candle flame is supposed to be under a bolt loaded with washers that are inside the smallest planter. This in turn will turn the washers red hot. That's where the heat comes from. As far as this really warming up a room with no heat, no way. I've built two different versions of this to try and heat my garage office, 35 degrees in the winter. Didn't make a bit of difference.
Paravival (author)  artistajg8 months ago

I wouldn't call it "All wrong"...The stainless steal that is present is awfully hot up inside those ceramic pots. And I'm seeing higher readings radiating off of this thing so idk! You prob know more that me but I wouldn't call it "all wrong". If anything it just looks more presentable on a counter than any other version I've seen. I guess what I like about it is I just keep it right next to my laptop so when I'm online/Instructables it keeps me toasty.

mampoer8 months ago

A small correction to step 5, you didn't use two big bolts as your spacers, you used two big NUTS.

Paravival (author)  mampoer8 months ago

Thanks Mampoer!

All Fixed. The images take me so long to make that I rush through the writing portion!

Anthony

Grunambulax8 months ago

I think that this works because it becomes a radiant heater. It will capture and release heat right around the device itself. Obviously it is not generating more heat than the candles per se. With the candles, the heat is partly radiant but mostly dissipates upward quickly as there is nothing to contain it. It would be interesting to use thermal imaging to contrast this with three candles per se.

madmedix8 months ago

It works, doesn't work…who cares? This is the perfect project to get a young one started into thinking like a 'maker'. Play with the materials, sizes, configurations and see what happens…I like it.

Misac-kun8 months ago

I wonder if this same principle could be applyed for cold dessipation. (Brazil is just like hell by mid day on summer)

jmwells8 months ago
I put three holes in the bottom of the bigger one, like you did on the plate. Seems to add a little convective draw. Spreads the heat a little.
hdmotorc8 months ago
You might get those readings close to the heater although, there is just not enough BTU's in tea light candles to heat up ANY room.
Paravival (author)  hdmotorc8 months ago

I mean...My room reads 62. Then when I close my door and put it on for
an hour. My WHOLE room goes up at least 7 degrees every time.... Soooo.
Ya maybe I can just defy physics or something. And my room is pretty
big. If It was a small 6 x 8 office or something, I bet my money on it
heating the whole place way more than 7 degrees. You can't even touch this thing when it's
running it's literally 200+ degrees when it's on. But I'm not
scientist I just like building stuff (: Hell I forgot what BTU stood for, I had to look it up!!!

Cool. I saw one on Facebook and wanted to make it. My pots were too close in size to try it. I need to buy some. Instead I researched it. Never found any real info that claims it is possible to work. A lot of info that says it don't and won't. I think it's cool. I will make one like yours because if you say it works what can it hurt. I'd only be out like $10. Plus it looks pretty cool. I'll try it.
My room will be 12x20 with 9' ceilings. We will see.
Paravival (author)  hdmotorc8 months ago

It's at least a nice desk warmer. I have it next to my laptop and it keeps me warm!

MikB hdmotorc8 months ago

Never mind the physics, and boring theory, and common sense. These things are all over the internet and so they must work :)

miscast8 months ago

Perfect for camper or tent!