Appendix G
Insulated Hot Box
What This Project is About
To start at the beginning, the original idea for this project started out as a way to keep things hot after they have been heated in a campfire or solar oven. The reason this is useful is that, as we have been doing our own preparations for things, we realized that one thing that we need a lot of in our daily living is hot water for things like cooking, dishes, laundry, bathing, etc. For dishes and laundry, you can get by with cold water, but it is quite a bit better to have hot water if you can get it, and certainly for the other things you really do need hot water, especially during the winter when you could get hypothermia trying to bathe in cold water. So there are just really a very large amount of things you need hot water for. And this is where the problem comes in, because if you are in a situation where resources are very limited, if you keep having to reheat the same water, you are using up resources that could be used for something else, and it could become a large waste of resources.
Another thing we realized is that, if using mostly solar type stuff, one downside is that you can’t really get hot water on cloudy days or at night if you want something even basic like having a cup of coffee or tea. And in those instances, what you really need is a way to heat water up when it is sunny, then keep that water hot for hopefully days on end during a storm or when it’s cloudy.
If one has access to a lot of wood to keep a campfire going, this of course isn’t as much of a problem, because you do have a way to heat things when it’s cloudy or at night, but even with a campfire, something like this can still be quite useful because of the way that it allows you to maybe only have to make a single fire in the morning to heat up a large batch of water, which could be put inside of the box and used throughout the day, instead of having to keep a fire going all day long as one has to keep on heating water over and over again when you need it. Also, if you’re campfire is outside, one still has the problem that you can’t really use it during a time that it’s raining, or when there is a blizzard. So even with a campfire, having something that you can keep things hot in would still be quite useful, because you wouldn’t have to spend as much time and resources trying to keep a fire going all day long, as you keep having to heat up water all day long, and you can still have hot water when it’s raining or blizzarding.
So with those things in mind, in comes this project and the idea of, what if you made basically a heavily insulated wood box that would function like an ice chest, only instead of trying to keep things cold, you built it in such a way that it could handle keeping really hot things hot. This way one could heat up a pot of water, leave it in the box, and hopefully it would stay hot for even several days, instead of just half an hour or so. And because of this, one could have hot water whenever they needed it, whether it was cloudy, night time, raining, or blizzarding, and one also may not even have to keep a fire going all day long, unless they needed to cook other things. And if one did have to cook things, at least the water would already be hot.
Although, even though this is where this project started, while designing it and building it, we have also had some other ideas of how this insulated box could be useful. The first one being that, because of the way it’s made, you could also do limited baking in it and use it as a limited oven as well. The way that you would use it would be to heat up some completely dry bricks or stones next to a campfire, then line the bottom of this box with those hot bricks and stones. After that you would just set whatever you wanted to cook on top of those bricks or stones and cook your food. Since the box is so heavily insulated, depending on how hot the bricks or stones are, the inside of the box should stay quite hot until the food was done. If not, one could always add more stones or bricks if the temperature started going down. Because of the way the interior of the box has wood in it, I wouldn’t recommend using hot coals to cook things in it, since there would be a greater danger of fire doing that, but definitely hot bricks or stones that were around 300 degrees Fahrenheit should be totally fine.
Another way this box could be used actually came from a little bit of a miracle. Towards the end of the project, we were sorting through some stuff and ran across this very old textbook from 1925 that talked about these things called “Fireless Cookers,” and thee basic idea was that, you would heat up your food in a pot, then set the pot in an insulated box. Since the box would be insulated, this would then keep all of the heat from the pot inside of the pot and actually cook your food. You can find out more about these here: https://www.lowtechmagazine.com/2014/07/cooking-pot-insulation-key-to-sustainable-cooking.html and here: https://www.appropedia.org/Fireless_cookers. We hadn’t known this before reading about it, but this idea is something that is still in use today and can be bought on Amazon, although now days they are referred to as “Thermal Cookers,”: https://www.amazon.com/s?k=thermal+cooker.
The reason for bringing this up though is that, with the way this box is designed, it could also be used in the same way. It wouldn’t work as well because of how large the inner box is, which would mean that if you just put a single pot in there, most of the heat from the pot would be lost to warming the actual box instead of staying in your pan of food, but you could get around this by filling all of that empty space with blankets. If you did that, it could potentially work just as well as those “Thermal Cookers,” above, while being quite large to fit many pots inside of it if you needed to. So in the end, this is another very useful way of using this box, as a “Fireless Cooker,” or, “Thermal Cooker.” And it’s similar to the idea above, but instead of heating your food in the box, you heat your food outside of the box, then let it sit in the box until it’s done, which is more useful for things like soup, beans, or rice, whereas the idea above would be more suited to things like bread.
With all of that, another use of course is to use the box to just keep hot food hot, without actually trying to cook it, so that you might be able to do something like have a hot snack in the middle of the night, or if you are cooking things in a solar oven in the winter, you would be able to cook it during the day, then keep it hot until night when you actually eat it.
Finally, one more use is that, because of how insulated it is, you could use it to keep things cold too. Although, for this, there are easier ways, and less expensive, of just modifying a normal ice chest with more insulation, like these videos show:
https://www.youtube.com/watch?v=EQhpwtqERgE
https://www.youtube.com/watch?v=3g200ELToc4
https://www.youtube.com/watch?v=3loyvCQtazs
https://www.youtube.com/watch?v=aPXhi7psQUE
So that’s a bit about the project, the kinds of things it was made for, and why you might find it useful to have. To finish off this section, here are a few more pictures of the final insulated box:
Lastly, as with all the things I build, I just want to give credit to God for all the amazing ideas He gives during the designing and building of these things, because it is so much because of Him that they even work as well as they do :). He really is an amazing person, and it is always such a fun thing and a treasure to get to build these things with Him. The truth is, I never could do it without Him, whether it be through direct ideas He gives, as He talks about doing in Exodus 31:1-6, when He gave people the wisdom and understanding to create the things He wanted them to create:
"Then the Lord spoke to Moses, saying: “See, I have called by name Bezalel the son of Uri, the son of Hur, of the tribe of Judah. And I have filled him with the Spirit of God, in wisdom, in understanding, in knowledge, and in all manner of workmanship, to design artistic works, to work in gold, in silver, in bronze, in cutting jewels for setting, in carving wood, and to work in all manner of workmanship.
And I, indeed I, have appointed with him Aholiab the son of Ahisamach, of the tribe of Dan; and I have put wisdom in the hearts of all the gifted artisans, that they may make all that I have commanded you:"
or it's just because of His ability to make me in a way that I could create these things, it is always because of Him in the end that they exist, and not because of my own amazingness to do them. With each of us, when we are born and given life, we don't know why or how we are able to do the things we do, or why we are just naturally better at some things versus other things. While it is true that throughout life we can learn new things and become good at things, even this ability to learn and grow is something that none of us know how we do. We just are who we are, and we don't have an explanation for it. But if none of us actually know how we are able to do what we do, how can we then take credit for it? It is only because of God's amazingness to create us in a way to do these things, that we can then do them. So is it not God, the one who made us able to do the things we do, the one who should have the glory for what we do? And in this way, even when He doesn't give ideas for things directly, it is still only because of Him that I can create these things.
The story of Nebuchadnezzar being turned into an animal in Daniel 4 really shows this as well, that without God's ability to make us understand life and how to create things, we never would be able to. Our understanding of things and ability to reason is only as much as what He gives us. I'll just quote a little bit of the chapter here:
"All this came upon King Nebuchadnezzar. At the end of the twelve months he was walking about the royal palace of Babylon. The king spoke, saying, “Is not this great Babylon, that I have built for a royal dwelling by my mighty power and for the honor of my majesty?” While the word was still in the king’s mouth, a voice fell from heaven: “King Nebuchadnezzar, to you it is spoken: the kingdom has departed from you! And they shall drive you from men, and your dwelling shall be with the beasts of the field. They shall make you eat grass like oxen; and seven times shall pass over you, until you know that the Most High rules in the kingdom of men, and gives it to whomever He chooses.” That very hour the word was fulfilled concerning Nebuchadnezzar; he was driven from men and ate grass like oxen; his body was wet with the dew of heaven till his hair had grown like eagles’ feathers and his nails like birds’ claws. And at the end of the time I, Nebuchadnezzar, lifted my eyes to heaven, and my understanding returned to me; and I blessed the Most High and praised and honored Him who lives forever:
For His dominion is an everlasting dominion,
And His kingdom is from generation to generation.
All the inhabitants of the earth are reputed as nothing;
He does according to His will in the army of heaven
And among the inhabitants of the earth.
No one can restrain His hand
Or say to Him, “What have You done?”
At the same time my reason returned to me, and for the glory of my kingdom, my honor and splendor returned to me...Now I, Nebuchadnezzar, praise and extol and honor the King of heaven, all of whose works are truth, and His ways justice. And those who walk in pride He is able to put down."
So I really do give Him the glory for what He has done, whether it's giving direct ideas, or creating me in a way that makes it possible to think through these things, and I just hope that my expression of Him will be a blessing in your life that shines with the incredible love and goodness that is in His heart. Because this is the real and amazing purpose of why He does give these things. They aren't just for our own use, but to love others with them. This was really what John the Baptist was trying to say in Luke 3:7-14 when he talked about giving your extra things to others that don't have what you have:
"Then he said to the multitudes that came out to be baptized by him, “Brood of vipers! Who warned you to flee from the wrath to come?...And even now the ax is laid to the root of the trees. Therefore every tree which does not bear good fruit is cut down and thrown into the fire.” So the people asked him, saying, “What shall we do then?” He answered and said to them, “He who has two tunics, let him give to him who has none; and he who has food, let him do likewise.” Then tax collectors also came to be baptized, and said to him, “Teacher, what shall we do?” And he said to them, “Collect no more than what is appointed for you.” Likewise the soldiers asked him, saying, “And what shall we do? So he said to them, “Do not intimidate anyone or accuse falsely, and be content with your wages.”
As though to say, "Use the things of this earth to bear good fruit and love others with it, because it's all going to be destroyed anyway. Put a purpose to it and do something good with it. Use the things in this life as a tool to store up treasure in heaven instead of here on earth." As Yeshua (Original Hebrew name of Jesus) also says in Matthew 5:16, let your light shine so that others may see your good works, and glorify God, and come to know God, because of them:
"You are the light of the world. A city that is set on a hill cannot be hidden. Nor do they light a lamp and put it under a basket, but on a lampstand, and it gives light to all who are in the house. Let your light so shine before men, that they may see your good works and glorify your Father in heaven. "
So it is in that love He has given these things, for as He says in Matthew 6, He knows the things that we need in life, and as such a loving Father, is so glad to help, and it is also in that love and in His love that I give them as well, hoping that what He gives out of that love will be a help to you as it has been to us.
Insulated Box Performance
For the performance of this Insulated Box, you can find all the data we have collected so far in the spreadsheet labeled "Prepping List_Appendix G_Insulated Hot Box_Data_Performance." To give a summary of what can be seen in there, so far we have tried a couple different ways of using it...
Using It to Keep Water Hot
For trying to use the box to keep water hot, so far we haven’t had great success with it, and it’s not because the water didn’t stay hot, but because when we tried having four large Carafes of water on the inside and one large Carafe of water on the outside, they didn’t seem to have too much of a difference in temperature. This can be seen in the second keeping water hot test we did, where the water started out at 190 degrees and took about 4 days to go down to around 100-120 degrees depending on the Carafe. There did seem to be a small difference, but not the large difference we were expecting. At this point, we don’t really know why it’s like this for sure, but it does seem to be the case. With the Carafes on the inside, we did notice that they had a fairly large range of temperatures that they were at, so there is one possibility that the Carafe on the outside was just sealed much better than the ones that were on the inside, therefore causing the water to stay hotter longer, but there isn’t any way to know for sure until we have tried that Carafe on the inside. The Carafes we used would have been similar to this one here, only much older: https://www.amazon.com/Coffee-Carafe-Thermos-Dispenser-Insulated/dp/B01MRGIZE9.
However, even though the Carafes by themselves didn’t have too much of a difference in temperature, there are still some advantages you get from having an insulated box like this, and the main one is that it still allows you to add things like really hot bricks that have been in a fire or something like that inside of the box with the Carafes. We have not tried this out yet, but this should give a much larger difference in temperature. There is also the advantage that if you are using it on a constant basis where you are reheating the water every day or two, the water should start to stay hotter longer because the actual box would have started to heat up at that point and not as much heat would be transferring to the box anymore. This is again something we haven’t tested yet, but in theory anyway, this should start to happen.
Using it as a Fireless Cooker
We have also tried using it as a “Fireless Cooker” or “Thermal Cooker” and basically just heated some water and whole oats until they were boiling, or about 190 degrees, then put it into the Box with towels covering it. It should also be mentioned that the pan we were using was a small dutch oven pan, about the size of this 2 quart pan but maybe a little smaller: https://www.amazon.com/Lodge-Pre-seasoned-Cooking-Basting-Baking/dp/B00008GKDU. And the result of these tests have been pretty consistent where it takes about 6 hours for the temperature of the water in the pan to go from 190 degrees to 110 degrees. We haven’t tried having a pan on the outside and one on the inside to see a comparison for this, but the oats are cooked by this time, and it definitely does work to cook things this way.
And that’s all so far for the performance of the Box.
Building the Insulated Box
Preview of Instructions and Images of Real Life Build
Since these instructions are quite long and everything can already be downloaded for free in the "Downloadable PDFs" section to the left, here is just a preview of those instructions and some images showing what is involved with creating this. All of these images will also be in the PDF along with further explanations for things.
Also as another note, if you decide to build this project, as will be mentioned in the PDF there is a spreadsheet with links to all of the supplies needed to build this project, which is also found in the Download section to the left, under the file labeled, "Prepping List_Appendix E_Solar Water Heater_Data_Cost." It "should" :), be a complete list of everything used in the project and also has the cost of each item, as well as measurements for cutting most of the wood.
Now on to the preview:
