Multi Fuel Heater System

I'm not sure if I have gone on my rant about heat yet, but one thing that I have noticed about most of the Tiny houses I have visited is that they use a propane heater to generate heat in the cold seasons. Alot of the time it is a marine heater mounted on the wall hooked up to an external propane tank or something similar. This seems like a complete waste to me.

Heat is the lowest form of energy. In many cases it is the product of inefficiency meaning that it really is waste. Think about your computer for a minute, after you have been using it for a while you can feel it and it will be warm or even hot. No this isn't because of your lap, it is because of the resistance in the wires and the chips used. This resistance is translated to heat and means that more power is required by your battery to perform the tasks it needs to. Now think about an incandescent light bulb. These little things are built to provide so much resistance that the filament actually glows white hot with heat and produces light. The average light bulb uses 75 watts to make light. That is ALOT of energy just for light. To put it in prospective the average laptop adapter is 60 watts, meaning that an ENTIRE COMPUTER can run on less power than most light bulbs. My laptop adapter runs on 30 watts [woot for netbooks!]. HALF of that lightbulb, and I can watch videos, surf the internet, draw, program, and write these posts for you guys, when the lightbulb can only make light.

Personally I think that heat should never be used just to heat. If I am going to be using the energy and resources to generate heat to heat the tiny house I want it to be doing something else too. If you look at my water heater design the copper pipe is wrapped around another tube, but that tube isn't the exhaust. I have a single burner doing SEVERAL different things AS WELL AS heating the house when it is needed. The heat generated is used to incinerate human waste into sterile ash, it is used to heat water, it is used to evaporate greywater when the solar greywater system isn't operational because of the weather [no sun] AND it's used to heat the house when I need heat in the house. Although, I live in Austin, Texas, and it doesn't get too cold here too often, and it rarely gets so cold that the heat produced by my body, my computer, my refrigerator and my cooking appliances isn't enough to keep the house at a comfortable temperature for me. [I like it to be cool most of the time] But I would have the option of using this system to heat the house if I did need it warmer than it is.

The propane heaters I see are crazy inefficient. Not in the fact that they are actually physically inefficient, but the fact that they use propane [not a sustainable resource for MOST off grid applications] to generate heat, and that's it. and what's worse, is that much of the heat is piped up and out of the house as exhaust! These systems are like lightbulbs to me. They do one thing, and they use alot of energy to do that one thing, and even aster using alot of energy, they also have alot of waste. CRAZY I SAY! So I thought up a system that can burn several different fuels to create the heat that is needed to perform whatever it is needed for. Heating, cooking, incinerating, generating more fuel in the form of oil [I am going to do a post on this system later, but I am really excited about it. ZERO WASTE!] Anything you need heat for. This system can provide for, AND it can do it burning whatever fuel that you can use.

It is pretty basic actually. It is built around a waste oil heater. [Read: pan full of burning oil]
Underneath the burn pan is a propane ring which has two purposes, preheat the oil in the pan, and generate heat. The ring can be moved above the pan if there is no other resource available for heat generation [NOTE: the chances of that happening are VERY slim. Fuel is everywhere, and propane shouldn't be wasted like that.]
The gas ring itself is multi fuel. The input hose is spliced with two hoses, one to the propane tank, and the other to a gasifier [if you have one that is, they are large in respect to how much fuel they produce, However if you want to get the most out of your carbon based solid fuels, a gasifier is for you. I will do a post on how to build one later. Or you can check out FEMAs post on how to make one.] If you don't have a gasifier, you can  hook it up to a methane generator, an hho generator, or any other type of gaseous fuel generator. [note: I will make a post on how to build each of those too...later]

On top of the pan you can place a solid fuel colander [A heavy walled shallow bowl with holes in it for air flow.] and burn solid fuels in there, you can burn wood chips, paper, sawdust blocks, pellets, sticks, small branches, any solid fuel.

The best part about about this system is that you can build it just about anywhere you want. Inside a wood stove, inside a 55 gallon drum, outside on the patio, wherever you want it! It can be as big or as small as you want it, and can run on every fuel I can think of. Solids, liquids, or gas, in one unit. It's simple enough for anybody to build with scrap materials, and flexible enough for most applications.

In any heat generation system, alot of heat is lost through the exhaust. In an effort to get the poisonous gasses produced by the heater out of the house, they are piped out in the most straightforward manner, this usually means that most of the heat is piped out meaning the fuel used to generate that heat is wasted. This is a total bummer to me. But one thing you can do is to run as much exhaust through your house as you can. If you have  the space, pick a wall. run your exhaust pipe left to right on your wall with a rise in it so the smoke will...rise. but you will be pulling the heat out of the exhaust as it runs through the pipe until it is room temperature at the output and leaving your house.

But this Isn't enough for me. Because solid fuel stoves usually burn at around 30% efficiency [I know there are some wood stoves that advertise 70% efficiency but that's like saying diet coke has zero calories, don't lie to yourself] This is usually because the fire doesn't get hot enough to burn the fuel completely. What you need to do is insulate the first five feet or so of exhaust pipe heavily. You also need to insulate the combustion chamber heavily. This will raise the temperature extensively and allow for a complete combustion, meaning more heat coming out of the exhaust, and less fuel being used, and NO SMOKE!

You can also use a peltier cell attached to the pipe to generate electricity. This will not create much electricity but you can use it to power a small dc fan that will circulate the hot air all around the house. Don't attach it right to your combustion chamber because it will melt the solder inside the peltier cell and make it not work.

Below is a pic of the burner setup. If you think that you will primarily be burning wood/solids for heat I wouldn't recommend this system, I would say use a Rocket Mass Heater because they are AMAZING! [I will do a post on this wonderful device soon]

This heater is mainly designed to be a liquid fuel heater [waste oils] With attachments to burn solid and gaseous fuels. The exhaust method can be used with anything that produces a heated exhaust [OR a cool exhaust to keep places cool in the summer!] Look up geothermal heating/cooling for more info!

If you have any questions feel free to ask!

Here are some links to Rocket Mass Heaters to keep you entertained and such while I get around to writing a post on them. [EDIT: HERE IS THE POST!]


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