alcohol stove comparisons

Posted by: Bike_packer

alcohol stove comparisons - 10/03/17 08:56 PM

I have built 4 alcohol stoves in the last year using plans from the Zen Stove website.

I have made the cat can stove and the min zen sideburner stove from this page Chimney stoves

I also have made this basic low pressure sideburner stove Sideburner stove

And I also made this low pressure top burner open jet stove which is the second stove pictured on this page Pepsi can stove

The side burner stove was the least efficient for me since I use a narrow bottom pot and the flames had a tendency to go up the sides of my pot and the heat transfer was not very optimal for boiling water. I designed a wind screen/pot stand from an empty fruit can and 2 bike spokes and with the pot a couple inches above the Top Burner stove, the flames hit the bottom of the pot and I could get a rolling boil on 20 ounces of tap water in a little over 7 minutes. It definitely helped to keep the lid on. So since last spring I have been using this set up at camp sites with excellent results. I cook Ramen and make morning coffee with this gem. Today I got the itch to experiment and I decided to re test my zen chimney stove against my top burner stove. I was surprised at my results. The open jet top burner stove was surprisingly INEFFICIENT compared to the zen chimney stove. This shocked me as I thought basic chimney stoves were supposed to be relatively inefficient compared to a stove that burned the vapor from tiny jets. I used a syringe and put exactly 3/4 of an ounce of HEET in each stove and lit them. I started timers for each one. At approximately 7 minutes and 6 seconds, the Pepsi can stove ran out. The Zen chimney stove kept burning strong and didn't run out until 9 minutes and 40 seconds!!! Can anyone tell me if this is common for these 2 stoves? I would have expected the readings to be the other way around.

Here's a few pics of it in action last spring with my windscreen.



Posted by: BZH

Re: alcohol stove comparisons - 10/04/17 03:46 PM

If I understand you correctly you are comparing your homemade pepsi can stove to a professionally built (and optimized) Zen Chimney stove. Seems reasonable to me that you couldn't be a pro... I know I wouldn't be able to.

The longer burn time, means lower flow rate out of the stove and it allows for greater time for the water to absorb the heat. That (in general) makes the stove more efficient.

BTW, I built an excel spreadsheet for some people in the community to calculate stove efficiency. I got a bit carried away and ended up with what I consider a pretty refined tool. Here it is if you are interested:

https://drive.google.com/open?id=0BwVBql46i9hbUE9HUm0xN3MwTWs
Posted by: Bike_packer

Re: alcohol stove comparisons - 10/08/17 09:29 AM

Originally Posted By BZH
If I understand you correctly you are comparing your homemade pepsi can stove to a professionally built (and optimized) Zen Chimney stove. Seems reasonable to me that you couldn't be a pro... I know I wouldn't be able to.

The longer burn time, means lower flow rate out of the stove and it allows for greater time for the water to absorb the heat. That (in general) makes the stove more efficient.

BTW, I built an excel spreadsheet for some people in the community to calculate stove efficiency. I got a bit carried away and ended up with what I consider a pretty refined tool. Here it is if you are interested:

https://drive.google.com/open?id=0BwVBql46i9hbUE9HUm0xN3MwTWs



uhhh.....no.... lol Comparing a homemade pepsi can stove to a homemade chimney stove. Both made by me.