For three years, my tenant, Randy, used a propane burner to heat his fifth wheel trailer. He was constantly having to ventilate, to lose moisture. But in the end, he still had to rip out much of the paneling in his living room. It was covered in black mould.
He built this very small pellet stove using 2 1/2 inch square tubing. It is gravity feed. The hopper is made from an old propane tank. It works pretty well and consumed under $1 per day in fuel in March. He expects to use as much as $2 worth of fuel per day, when there is snow on the ground.
This is by no means the latest technology, but it's a huge improvement for Randy. He spent $1500 on propane during his first year on the property. I expect that he'll get by with less than $200 per year now.
The place is nice and dry. He has seen my masonry stove, but wanted something mobile. Metal is his preferred medium.
I'll post results of the first full heating season when the time comes. We just finished a heat wave with highs in the low 40s. About 105 F.
I don't expect to see the stove in operation until at least October. I'll take more pictures then and give a report.
The portion by the burner, gets red hot. By the time the pipe exits the space, a hand can be held directly on the exhaust pipe. I'm guessing the exhaust temperature to be about 150 degrees.
The exhaust pipe, is a left over exhaust for a big truck. It's a fairly thick gauge of steel.
The pellets flow down onto a relatively small ceramic burn tray.
That's about all that I remember . I won't see the stove for at least a month.
Randy's stove has been operated for most of a heating season now.
On the very coldest days, it consumes about $2 worth of pellets. His propane heater consumed up to $15 during a similar day.
The place was always dripping wet, when he burned propane. Now it's nice and dry.
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The pin with the flat plate, prevents material from flowing from the hopper to the burn chamber. When it's time to light the stove he pulls the pin and the chamber fills.
With the baffle removed, the stove will continue to work until all pellets in the hopper are exhausted. This much heat is usually not needed.
When the pin is reinserted, it prevents further flow from the hopper.
It takes about one hour on the low air setting, for the stove to use up all of the pellets in the neck. A one hour burn is all that's needed in the warm days of spring. Trees are in flower already.
On days when Randy leaves his little dog home, he starts the stove and then leaves it with one hour to burn by inserting the pin baffle.
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The lighting procedure is rather awkward. Two propane torches are used. One is put up the chimney to begin airflow and the other is put to the burn basket. They are run for about two minutes. He has emptied one canisters so far this year.
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In order to observe what's going on, he installed a glass window. A piece of salvage glass from a stove was taken to a glass cutter. The guy who cut the glass, did it for free, since he liked the idea of a pellet stove with no electricity needed.
The stove window, gives just enough light for maneuvering around at bedtime. It gets black dark at my place during the winter when clouds prevent any starlight from coming through. The night light function, was a welcome bonus.
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Randy has tweaked his design several times. This one may eventually go to his shop. A new, improved model will heat the trailer.
The stove works much hotter now, compared to the first trials in the spring of last year. The burn box and air intake are larger. This has resulted in much hotter exhaust. I'm guessing 300 F or more. A water jacket may be added to this or the next model. Randy has also said that he may include a radiant barrel. If flat on top, the barrel could become a cooking or water heating surface. A 2 ft long propane tank laid sideways, with a flat surface replacing the top third of the round, is under consideration.
Randy has burnt out two fire baskets. The new one will be stainless. In order to get better burn temperatures he's increasing the pipe to 6 inch in that area and using something fire bricks two line it.
He used to burn $10 worth of propane on a cold day. Now he goes through about $1 worth of pellets on a similar day.
How tall is the exhaust, and is it a straight shot up through the roof???
A few dimensions, and/or a picture with a tape measure from two or three directions would be uber helpful.
As noted in other threads, a hot fire with direct impingement on steel absolutely will eat the steel fairly quickly. There are safety and fire concerns with this, but the design shows great potential...