Thread: Shed heating options

Originally Posted by Oldneweng

"Pretend"? Not a good name for them I thought.

The sharp bend promotes turbulent flow but at the end of the day if the flue goes straight up, a lot of heat goes with it. Some of these things being promoted as rocket heaters are no where near the concept that DJ posted, they just have the shape.

Michael

Originally Posted by Michael G

The sharp bend promotes turbulent flow but at the end of the day if the flue goes straight up, a lot of heat goes with it. Some of these things being promoted as rocket heaters are no where near the concept that DJ posted, they just have the shape.

Michael

"Pretend"? was intended as sarcasm. I agree entirely with what you say, but I did say "bends". Note the "s" on the end lol. Yes if the flue goes straight up the heat does too. Not much different to a fireplace then.

My current slow combustion has a baffle plate (as do nearly all) at the top of the firebox so the gasses go to the front, up around the plate then to the back to go up the flue. This would seem to be doing a very similar thing to the rocket heaters. I used to have one that had a steel pipe about 100mm diam pass from side to side above the baffle. This was supposed to extract extra heat out of the gasses. I cannot say if it did or not! It worked very well but then it did have a BIG firebox.

Dean

Thanks Jchappo for posting the youtube video of the rocket stove. I had never heard of them before. Talk about living under a rock!

I have since done much reading on the Rocket stove concept. It seems to me that the "real" ones are made to be space heaters and incorporate some thermal mass that gets heated by the exiting exhaust gases. Smaller versions have the flue plumbed straight up without the thermal mass and a pot is placed on top for cooking. What they both have in common is the combustion chamber and the fact that they are insulated. The insulation around the combustion chamber reduces heat loss and creates very high combustion temps which improves combustion and reduces unburnt gases. The open top version would obviously not be practical in the shed and so the type shown in the youtube video would need to be made, or some similar version.

For some time now I have been thinking of making a small wood stove for camping, similar to the many made by punters out there using a 9 Kg LPG bottle. Now that I have seen these, I have no doubt that these would be much more efficient than the more common variety. The flue gases going straight up is not a real concern as this is no different to the use on an LPG stove. A skirt that raises the sides and causes the gases to pass from under and pass along the sides further increases efficiency.

Last weekend I went camping which ended up a rather rushed packing and shopping job. Son and I got to our destination only to find a stove without any LPG. No big deal, I usually prefer campfire cooking anyway. Do you think I could find any dry firewood? Everything I cut and split was wet through, very unusual even in winter. Plenty of kindling and dry twigs though. Hence my light bulb moment when I saw the rocket stove idea!

Simon

Originally Posted by jvb

I bought one of these from Supagas years ago.

Attachment 276406

If your shed is large enough (there is a minimum shed size/volume) then they are great. More of a local heater, you can move it around to where you are working.
It will end up heating my whole workshop. And no mucking around with firewood, enough trouble keeping up with the wood heater in the house.

I'm leaning towards one of these. Not sure if they are available over here in WA though....I have been looking....
Steve

Originally Posted by Sterob

I'm leaning towards one of these. Not sure if they are available over here in WA though....I have been looking....
Steve

they will be available in WA...try Aira if they have a office over there

Well, I have been using my Kero heater solidly all week and I dont think Ill be buying anything else anytime soon. Granted the temps at night have been much higher that last week, but nontheless...the other night I had to take my jumper off as I was getting too warm down there. Its a beaut little thing, probably 30 years old, and produces about 3kw of heat (10,000 BTUs). Dead easy to light, silent, and despite my suspicions it doesnt smell at all. It uses 300mls of Kerosene per hour which at woolworths prices is very expensive, but I hope to source some cheaper for long term use. Very clever device.

Originally Posted by 19brendan81

Well, I have been using my Kero heater solidly all week and I dont think Ill be buying anything else anytime soon. Granted the temps at night have been much higher that last week, but nontheless...the other night I had to take my jumper off as I was getting too warm down there. Its a beaut little thing, probably 30 years old, and produces about 3kw of heat (10,000 BTUs). Dead easy to light, silent, and despite my suspicions it doesnt smell at all. It uses 300mls of Kerosene per hour which at woolworths prices is very expensive, but I hope to source some cheaper for long term use. Very clever device.

Any chance of a pic Brendan??

Phil

I made a list yesterday of all the things I need to take photos of to update several threads on here, but then I left the list at work. The heater is on that list. I will try again over the weekend though.

Originally Posted by simonl

Thanks Jchappo for posting the youtube video of the rocket stove. I had never heard of them before. Talk about living under a rock!

I have since done much reading on the Rocket stove concept. It seems to me that the "real" ones are made to be space heaters and incorporate some thermal mass that gets heated by the exiting exhaust gases. Smaller versions have the flue plumbed straight up without the thermal mass and a pot is placed on top for cooking. What they both have in common is the combustion chamber and the fact that they are insulated. The insulation around the combustion chamber reduces heat loss and creates very high combustion temps which improves combustion and reduces unburnt gases. The open top version would obviously not be practical in the shed and so the type shown in the youtube video would need to be made, or some similar version.

For some time now I have been thinking of making a small wood stove for camping, similar to the many made by punters out there using a 9 Kg LPG bottle. Now that I have seen these, I have no doubt that these would be much more efficient than the more common variety. The flue gases going straight up is not a real concern as this is no different to the use on an LPG stove. A skirt that raises the sides and causes the gases to pass from under and pass along the sides further increases efficiency.

Last weekend I went camping which ended up a rather rushed packing and shopping job. Son and I got to our destination only to find a stove without any LPG. No big deal, I usually prefer campfire cooking anyway. Do you think I could find any dry firewood? Everything I cut and split was wet through, very unusual even in winter. Plenty of kindling and dry twigs though. Hence my light bulb moment when I saw the rocket stove idea!

Simon

Mention was made in the video about the heat release at the top of the insulated chamber as the direction of the gasses changed. I got the impression that this effect was repeated to some extent on the simpler stoves due to the cooking pot sitting on top. The base of this pot would absorb the released heat. This is only if the theory actually works as the video says tho.

From my point of view I am interested in the efficiency, as to heat a 4.5 X 9m shed with no lining at all is a tough ask. At work we use oak planks for oak flavour in wine. They are about to order a 40ft skip to take the used vintage planks away. They get used as mulch I believe. This is after everyone who wants has taken their supply. These are mostly used in fire drums etc. I have quite a few tonnes of them here. They are ideal for shed heating but I don't want to have to bring home a trailer load every week.

Sizes vary. We have been using packs of thin boards about 125mm wide 800mm long that are strapped together with spacers to seperate each board. Thes are not so good. They have been discontinued tho. Other planks are 5-10mm thick 40-80mm wide and 800mm long. These are good. We bought a cheap SCMS (Saw) just to cut these up for inside stoves as kindling and to get them hot. We have also just started using 20X20mm oak. Will be a while before they are available tho.



Dean

Originally Posted by 19brendan81

Well, I have been using my Kero heater solidly all week and I dont think Ill be buying anything else anytime soon. Granted the temps at night have been much higher that last week, but nontheless...the other night I had to take my jumper off as I was getting too warm down there. Its a beaut little thing, probably 30 years old, and produces about 3kw of heat (10,000 BTUs). Dead easy to light, silent, and despite my suspicions it doesnt smell at all. It uses 300mls of Kerosene per hour which at woolworths prices is very expensive, but I hope to source some cheaper for long term use. Very clever device.

Is this different from a normal kero heater? I have never been a big fan of them due to cost. Years ago we were told to place a bowl of water on top to get rid of the fumes. I was sceptical but I have to admit it did seem to work.

Just got an update from SWMBO. The more modern one (Only 30 yrs old) which we have dumped needed the bowl of water. She has used an "old" one in our work room (6m X 5m) and it is very good for fumes.

I have pondered the idea of a waste motor oil heater using the burner idea which I am planning on making for my foundry when I get some time. I have years of used motor oil saved up, mainly due to the difficulty of disposal of it.

My best solution would be to build a new lined shed.

Dean

Hey Dean,

I used waste motor oil for my foundry for a while - never again. Despite the oil burning without any smoke the smell was really bad, and it lingered. Theres no way in hell id use it for a heater which would be on for some hours (vs the 20 mins or so my furnace fired for). My neighbors would hang draw and quarter me.

My heater is similar to this

Corona Wick Portable Kerosene Auto Start Autoignition Heater Japanese | eBay

I'll put an actual photo up shortly.

I don't spend much time in my shed in really cold conditions but I still regret not lining at least the roof. The walls are slowly getting lined with yellow tongue but that's more for functionality than for insulation. Per sq metre I find yellow tongue the cheapest & easiest lining unless you have "other" sources!

Simon

Originally Posted by 19brendan81

Hey Dean,

I used waste motor oil for my foundry for a while - never again. Despite the oil burning without any smoke the smell was really bad, and it lingered. Theres no way in hell id use it for a heater which would be on for some hours (vs the 20 mins or so my furnace fired for). My neighbors would hang draw and quarter me.

My heater is similar to this

Corona Wick Portable Kerosene Auto Start Autoignition Heater Japanese | eBay

I'll put an actual photo up shortly.

I have not tried it yet. The smell may not be an issue with me but then it may. Who knows without trying it. If I used it for heating the shed I would have a sealed unit for air circulation and exhaust the fumes fairly high in the air, sending it on to the neighbours lol. As we live on a farm the wind is much more consistant than in a city, in direction and force. Our nearest neighbour is 1500m away so that is not much of a problem. The roos and bush chooks may complain tho! I intend to do the foundry work in my implement shed which is somewhat removed from the house.

The kero heater looks very similar to the one we tossed out, complete with the battery ignition system which we never used. I don't think it would do much in my shed. It is a very old shed.

Dean

This discussion has started me thinking on several fronts.

I have about 4 rolls of foil lined insulation. I don't know how long they are. I recently used up part of a roll insulating a dog kennel. It is a big dog kennel. I decided to make this one big enough for me and at least one dog. We have another one not much smaller. Our dogs (3) get well looked after. This other one is insulated with normal R3 house insulation. Not Chinese!

I could use these rolls of insulation to insulate the roof of my shed, for a start. I also have some rolls of mesh for underneath fragile roofing material. I could either support the insulation on the mesh under the roof beams or remove the roof sheets and lay the insulation on top of the beams with or without the mesh. Initially I thought of having a ceiling arrangement but soon decided against it.

I also have around 20 sheets of chipboard that I got very cheap. These sheets are old and far from perfect. I was planning on using them for shed shelving. I originally bought 10 sheets for about 10 bucks but the rest were going to be tossed so I got some more. The ones that were going to be tossed are still there lol. Anyway I thought of lining the sides with these using insulation behind them. I think I may have to seal them to prevent further deterioration.

More work!

Any comments or suggestions?

Dean

PS SWMBO says I have to insulate the rest of the house first. Sigh.