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I wanted to share my new method of heating greenhouse plants with waste vegetable oil. It's cheap or even free, eco friendly and easy to set up.
You only need:
- waste vegetable oil
- a small cup
- two hexagon nuts
- toilet paper
Stack the two nuts on top of eachother in the middle of the cup, they'll serve as a wick holder. Put the rolled paper in the hole of the nuts. The paper must be cut so it reaches a little bit above the border of the nuts. The underside of the paper wick must touch the bottom of the cup.
Fill with oil, but keep the level under the top of the stacked nuts to prevent the flame from drowning.
Wait until the wick is completely soaked with oil.
Light it like a normal candle. You'll find that it takes longer until it catches fire because vegetable oil has a higher boiling and flame point than candle oil or candle wax.
The heat output of the flame will be somewhere between 150 and 190 BTU, depending on the size of the flame and the type of oil you use. You can make additional burners to increase the heat output.
The best use of those little heaters is when you put them directly under a stone, marble or metal shelf with the plants on it. The heat will spread over the shelf and keep the roots warm, which is very important for most tropical plants. It's a good replacement for those electric heating pads which are used often.
You can use it as a candle too, by replacing the cup with one of those small tea light cups. It will burn for about 3-4 hours.
When using it as a heater for the plants you should use bigger cups so you won't need to refill constantly.
The toilet paper will slowly disintegrate because of the hot flame, but it should burn between 8-12 hours before you need to replace it with a new "wick". When you let it running out of oil, the wick will burn completely and won't work anymore. In such case you can make a small but tight dot of paper (around 0,1 inch in size) and put it in the middle of the top of the charred wick. Fill with oil again, let it get soaked and it will burn again for 8-12 hours. You can replace this paper dot 4 or 5 times before you need to replace the complete wick.
- the nuts and wick should be in the middle of the cup if it's made from glass, to prevent it to get damages from the flame heat.
- a soothing flame means that your wick is too long. Trim it a little and relight.
- works with all sorts of vegetable oil, but you might need to adjust the length of the wick when switching to another oil
- don't use gasoline, spirits and harmful liquids as fuel
- the oil must be free of water drops
- when using as a candle, you might want to add aromatic oils for a pleasant smell. The candle will be odorless untill it burns out of when you blow out the flame
- put the oil in a dispenser for bath or handsoap so you can refill the burners easier. You can even refill 'on the fly' while the candle is still burning because the oil doesn't spread inflammable fumes
- provide some ventilation if you use a lot of burners at the same moment, because they'll "breath" too. They might go out in an unventilated room when the oxigen gets low.
- the wick kan be replaced easier when you make use of tweezers
- some restaurants give away their waste vegetable oil at no cost. Ask them for your free supply of heating fuel.
- ofcourse I'm not responsible for any damages or injuries resulting from any use of this self made burner.
I have been working on a new heater which burns waste vegetable oil with a clean, blue flame. It's made from a canister and perforated metal strips and has an amazing heat output of nearly 15000 BTU.
There's only one drawback: the wick must be replaced every five minutes because it's not capable to stand the immense heat. This renders the heater useless, but I'm looking for a solution.
They're not suited for greenhouse heating, indeed.
I use them as a replacement for electric heating pads instead, which works great for tropical plants in my rather cold greenhouse.
For better heat output I have developped the heater you see in the last pic, which unfortunately doesn't work for longer than 5 minutes. I have posted it here, so other people can eventually post some ideas to improve it or use it as a base to develop their own heaters.
I have calculated the BTU output by using the heat value of vegetable oil, the volume oil I put in the burners and the time it took to consume all the oil. Then I came to a watt/hour value which I transfered into BTU values. Might sound like a nerd to do all these things, but it's just to practice my past studies in biochemistry :)
Just made an improved version of the veggie oil heater for greenhouses. It burns more efficiently, doesn't soot and the great thing is that you can make heaters at any desired heat output while the old version only gave around 150 BTU.
What you need:
- roll of toilet paper
- metal strip
- veggie oil
- saucer or bowl
and this is a version with a wide wick for more heat output. You can make it as wide as you need it for enough heat output. A wick of one feet will be sufficient to heat a greenhouse and it doesn't soot. This is because the wick is flat which allows more air to pass the flame for a better combustion than regular candles or oil lamps. Just make sure that the wick is cut evenly over the complete width.
- Use metal cups or saucers if you have more than 1/3 inch of wick because the heat output will cause the glass to break
- Put burners on stone tiles, a layer of water or a wet towel if they have more than 1/3 inch of wick to prevent overheating
- Thin wicks are easier to light but need to be replaced more often. Thick wicks are harder to light, soot easier but last longer between replacements. A 1/3 inch wick with 8 layers of toilet paper lasted about 20 hours before I needed to replace it.
- Veggie oil has a high viscosity so the wicks can't draw it very high. Use flat but big saucers with max 2/3 inch of oil for long burn times without needing to refill
- A metal or glass chimney held above the flame with metal wiring will increase heat output and efficiency. You can use one from an old Aladdin lamp (great lamps by the way :) )
- Only use veggie oil and avoid dangerous liquids such as gasoline, chloroform, spiritus, whiskey, …
- Wicks can easily be replaced if you use tweezers. Just pull the old wick out and put a new one in, and you're set for another 20 hours of heat/light considering you have enough veggie oil
- If it still produces soot, the wick is too long. Cut it back and relight.
Thanks you're welcome :)
It should work with any kind of oil, but if you switch from the one oil into the other I would keep an eye on the flame as some oils burn better than others. Sometimes it happens that a nice burning flame starts to soot when you switch to a better burning oil, so it means that you have to trim the wick a little or make it longer in the reverse case.
If I was you I would take profit as much as I can as I expect the price of waste vegetable oil will rise to the level of regular kerosene when more people get to know about this burner setup ;)
[quote="Cumulus79"]I have been working on a new heater which burns waste vegetable oil with a clean, blue flame. It's made from a canister and perforated metal strips and has an amazing heat output of nearly 15000 BTU.
There's only one drawback: the wick must be replaced every five minutes because it's not capable to stand the immense heat. This renders the heater useless, but I'm looking for a solution. [/quote]