[Marthale7]

Today I decided to test out making a sand battery. I had this old pot with a hole in the bottom, I then took two cans cut out the bottom on those and put inside the pot over the hole then filled the pot with sand fir the first layer. Second layer I cut down the can a bit so it would fit in the pot and I laid in another layer of sand. For this first go around I had temps at the bottom at 325 degrees and at the top at 165 degrees…. After this I brought is inside put a welding blanket inside the cooler and put the pot inside…. I noticed a large amount of moisture building up inside the cooler, which figures as the sand I used was from outside. I am formulating how I could improve the heating of the sand was a fun experiment.

[kaypea]

Interesting, how would you use it?

[Marthale7]

This being a proto type I am breaking new ground here. I can use a fan with it to blow heat to me, or I can use it as a hay box cooker or thermal cooker I am thinking, but since this is the first time I have made this I am exploring. I like sand better than water for heat storage as i can go to higher temps without worry of steam problem like water.

[BiggKidd]

Interesting way of moving heat around, I’ve done similar with rocks. If you want to get more heat in the sand you might consider using MANY smaller tubes over the single large chimney. That way it heats the sand more evenly and faster. With a fan blowing through it will also transfer heat to the wanted area faster.

[Marthale7]

Yes, I have been thinking that metal bolts might be a better option, something that would allow more airflow, perhaps fist sized rocks might work better….

As I looked closer at this I do believe either an auger, or putting the sand into pans, then dumping the hot sand into a container afterword.

I am thinking putting the sand into my rocket oven heating it up then dump into an insulated box might do better…

I have a few ideas going in my mind but just will have to test to see what works….

[BiggKidd]

How about a rocket stove made mostly from ammo cans a small one inside a large one with sand in between. With an easily removable chimney. Take it outside burn it to get it hot after it’s done simply dump the ashes and carry it in leave the feed chute open for air to pass in and out the the chimney access.

[Marthale7]

Interesting idea… make the stove itself the thermal mass….. Might work…. The idea I am working on in my mind is to have the stove outside, and the sand inside but transfer the heat to the sand via a pump and water heated by the rocket stove. Like a boiler.

[Hippocrates_Garden]

So, basically, a thermal mass. It may look a bit different, but a technique used for centuries variously known as “thermal mass fireplace”, “Russian Fireplace”, or the more recent “rocket mass heaters”. essentially the same idea. Heat up a mass, then let the mass radiate the heat over time. Even “Passive solar” buildings use a version of this, substituting the sun as the heating source onto thermal masses inside the house during winter.

[Marthale7]

Yes, I run a rocket stove group on MeWe, and I have been looking at all kinds of rocket stoves, gasifier stoves, and TLUD stoves.

My attention got caught on thermal mass when I visited a man who built a cob oven. From one firing he runs the oven 2 – 3 days and cooks over 6 turkeys at a time in it. It is a huge oven, but he did not use much wood to heat the oven…… Since that time I have been collecting data and trying different methods of using thermal mass. My idea is to have the thermal mass right outside my window, and then with thermostat pipe that heat into my home as needed.

I have also worked with heat retention, thermal cookers, hay box cookers and I want to learn how to use the thermal mass of sand to hold heat and use it to my advantage. Thus using old junk steel cans give me a starting point to see how to get started…

[Marthale7]

Yes, Earth Ships are famous for this….

I also do solar cooking… I know one guy who heated up steel rods to over 800 deg, he would then use the rods to cook on at night…. I want to harvest solar energy and use the rocket stove / oven to capture energy for cloudy days…. So testing what works and what does not.