@SunnyMoon2010 No. All things equal, a hotter fire is more efficient and releases more energy from the same quantity of fuel. In this experiment, we burned wood in the two stoves for an equal number of minutes. The amount of wood burned in each was nearly equal. However, since the stove with the bellows brought water to boil faster, it took less wood with the bellows to achieve 10 minutes of boiling. Forced air > more efficient combustion > less wood needed > fewer emissions.
I made a blower using a 2 liter plastic soda bottle with square hole cut into side and 12V computer fan metal taped to hole. Easily solar powered and/or car battery or smaller. Not super powerful but enough for cooking. Try it!
@mhee2b I made it for my 1 gal paint can (plus a tomato can) woodgas stove. I powered it with a car booster pack which is basically a car battery and I would keep it charged with car batter solar panel, quite small. But it could run on smaller. At woodgascampstove site you can get a 2 AA solar battery charger which powers their stoves (I had 2 of them until I got smart and started making them) Just don't leave them out in the rain! My other panel can handle rain. Those flex panels work too.
@apples13able I bilt a heineken rocket stove & while camping a fren had a foot air pump for his raft. We would sit near the stove and occasionally pump the air to increase flame & btus.I wanna bild a Jtube rktstove for less effort w fuel feed. Great that your teaching kids! I think the solar panel was under $25. But you could maybe hook up 8 D 1.5v batteries in series and hook a $25 solar panel to it altho the 2 AA solar charger is more compact... I like cheap & recycled/sustainable/effective!
@apples13able One last thing, I used a hair dryer on cool on the woodgasstove and heated 30 gal of water to 140 F using a 5/8 copper coil. Took 3 hours of constant fuel feeding. I want to refine the system. Need a camera! Eventually!
One thing you might want to be aware of is that when galvanized steel is welded on (heated) it can produce zinc oxide fumes. You might want to use plain steel or another metal.
Thank you. The "why" is to investigate ways to make wood-burning stoves use less fuel, less polluting, and more attractive to the billions of people who cook over open fires, today. Forced air is one avenue of investigation in this quest. ("The way to have a good idea is to have a lot of ideas.") To learn more, google:
Now this shows imagination at its best, not sure why you would need to do this unless your trying to use it like a blacksmith to shoe your horse. It defeats the purpose of the stove design. But, shows what you can do when you get away from an Xbox. Great job..
I used a fan with mine about 4 foot back works like a champ ( don't have this model stove but another rocket stove ) the advantage is I can use wetter wood.
Also, the air fuel mix of a fire might be optimized with bellows to more completely consume the wood reducing wood required and particulates created. More testing (and better measurement tools) required to see if a bellows design can achieve that.
Yes, you will have to feed a child a very little more if you make them pump the bellows. (Unless you call them in from soccer.) More importantly, the default cooking mode for almost half the world's population is open fire or inefficient cook stoves. This StoveTec rocket stove is dramatically more efficient than an open fire. The faster a stove is, the higher the adoption rate because people everywhere want to get dinner on the table quickly.
Very nice! Great experiment, simple and controlled. Hopefully you repeated it several times. I'm curious how you built your valves. They look pretty 'basic'--did you have any problems with hot air/sparks being sucked back into the buckets?
@doughpat , Valves were indeed rudimentary...probably a 10,000 year old design. Stiffer flaps attached to the ends of the sticks that closed the hole on the down-stroke and naturally opened on the up stroke. Surprisingly little air escaped through the valve. No problem with air/sparks being sucked back into buckets. Main issue was ashes being blown up into pot. A simple screen might address this issue. The volume of the 2 bellows were probably excessive for the size stove. Thanks.
it took 1/2 hour to boil water, not my cup of tea I rather use alcohol
TheOriginalStevenH 5 days ago
Did it use more fuel with the bellows ?
SunnyMoon2010 1 month ago
@SunnyMoon2010 No. All things equal, a hotter fire is more efficient and releases more energy from the same quantity of fuel. In this experiment, we burned wood in the two stoves for an equal number of minutes. The amount of wood burned in each was nearly equal. However, since the stove with the bellows brought water to boil faster, it took less wood with the bellows to achieve 10 minutes of boiling. Forced air > more efficient combustion > less wood needed > fewer emissions.
mhee2b 1 month ago
I made a blower using a 2 liter plastic soda bottle with square hole cut into side and 12V computer fan metal taped to hole. Easily solar powered and/or car battery or smaller. Not super powerful but enough for cooking. Try it!
apples13able 1 month ago
@apples13able Good thought. How much panel area and what cost for solar to run a 12V computer fan?
mhee2b 1 month ago
@mhee2b I made it for my 1 gal paint can (plus a tomato can) woodgas stove. I powered it with a car booster pack which is basically a car battery and I would keep it charged with car batter solar panel, quite small. But it could run on smaller. At woodgascampstove site you can get a 2 AA solar battery charger which powers their stoves (I had 2 of them until I got smart and started making them) Just don't leave them out in the rain! My other panel can handle rain. Those flex panels work too.
apples13able 1 month ago
@apples13able I bilt a heineken rocket stove & while camping a fren had a foot air pump for his raft. We would sit near the stove and occasionally pump the air to increase flame & btus.I wanna bild a Jtube rktstove for less effort w fuel feed. Great that your teaching kids! I think the solar panel was under $25. But you could maybe hook up 8 D 1.5v batteries in series and hook a $25 solar panel to it altho the 2 AA solar charger is more compact... I like cheap & recycled/sustainable/effective!
apples13able 1 month ago
@apples13able One last thing, I used a hair dryer on cool on the woodgasstove and heated 30 gal of water to 140 F using a 5/8 copper coil. Took 3 hours of constant fuel feeding. I want to refine the system. Need a camera! Eventually!
apples13able 1 month ago
Good input. Thanks.
mhee2b 2 months ago
One thing you might want to be aware of is that when galvanized steel is welded on (heated) it can produce zinc oxide fumes. You might want to use plain steel or another metal.
jjsjeffjjsjeff 2 months ago
Thank you. The "why" is to investigate ways to make wood-burning stoves use less fuel, less polluting, and more attractive to the billions of people who cook over open fires, today. Forced air is one avenue of investigation in this quest. ("The way to have a good idea is to have a lot of ideas.") To learn more, google:
aprovecho research center why cleaner cookstoves
mhee2b 2 months ago
Now this shows imagination at its best, not sure why you would need to do this unless your trying to use it like a blacksmith to shoe your horse. It defeats the purpose of the stove design. But, shows what you can do when you get away from an Xbox. Great job..
tigerb2 2 months ago
I used a fan with mine about 4 foot back works like a champ ( don't have this model stove but another rocket stove ) the advantage is I can use wetter wood.
marthale7 3 months ago
Also, the air fuel mix of a fire might be optimized with bellows to more completely consume the wood reducing wood required and particulates created. More testing (and better measurement tools) required to see if a bellows design can achieve that.
mhee2b 4 months ago
Yes, you will have to feed a child a very little more if you make them pump the bellows. (Unless you call them in from soccer.) More importantly, the default cooking mode for almost half the world's population is open fire or inefficient cook stoves. This StoveTec rocket stove is dramatically more efficient than an open fire. The faster a stove is, the higher the adoption rate because people everywhere want to get dinner on the table quickly.
mhee2b 4 months ago
Correction: Maybe a 3500 year old design. Iron Age started 1300 BC.
mhee2b 5 months ago
Very nice! Great experiment, simple and controlled. Hopefully you repeated it several times. I'm curious how you built your valves. They look pretty 'basic'--did you have any problems with hot air/sparks being sucked back into the buckets?
doughpat 7 months ago
@doughpat , Valves were indeed rudimentary...probably a 10,000 year old design. Stiffer flaps attached to the ends of the sticks that closed the hole on the down-stroke and naturally opened on the up stroke. Surprisingly little air escaped through the valve. No problem with air/sparks being sucked back into buckets. Main issue was ashes being blown up into pot. A simple screen might address this issue. The volume of the 2 bellows were probably excessive for the size stove. Thanks.
mhee2b 7 months ago