Hot Water off the Grid
When it comes to prepping, one of the many important things to think about is how you’ll get the hot water you need. Hot water is used for cooking, cleaning, bathing and many other important things we do every day. In the event of a total loss of power and/or gas, most people would be without a good way to get the hot water they need. It is possible to set up solar water heaters, or use generators, but those are often expensive and inefficient. Heating the water in a pot over an open fire is also a slow and inefficient process. The following guide will show you how you can make virtually unlimited hot water for a minimal investment.
What you’ll need:
The following items are needed to get endless hot water without electricity using this process. It is possible to substitute most of these items out with something else you may have on hand. Keep in mind with this guide, you should be able to find most of these items for very cheap, or even free, if you know where to look. So, gather these items together:
- A Rocket Stove – There are many types of rocket stoves available for sale. You can also make them with bricks or other items you can find. See the image below for an illustration of how they work. Basically, they are a small stove where you can add in pieces of wood, or other burning materials. It burns the fuel, sending all the heat straight up through the stove pipe at the top. These pipes can get 500-600 degrees inside very quickly when burning basic kindling wood.
- Stove Pipe – Get a large stove pipe that will go on top of the rocket stove. The wider the pipe the better. Just keep in mind that the pipe must fit snugly on top of the rocket stove to avoid heat loss.
- Copper Piping – Get a long length of copper piping, and bend it into a coil. The coil that will fit into the stove pipe. You can often find scrap copper pipe, which can be bent into a coil in a junk yard or any number of other places. A ½ – ¾ inch tube should be sufficient, though any size should work. You’ll also need some straight copper tubing, so don’t bend it all.
- Fuel – Fuel to burn in the rocket stove. This will typically be small sticks or kindling wood.
- Water Storage Tank – An old hot water heater works perfectly for this. As long as the hot water heater holds water, it will work.
- General Fittings & Shut Off Parts – Some pipe fittings to connect everything together. The specific size will vary depending on the size of copper tubing and what type of water storage tank you have.
Setting it Up
Once you’ve got all your parts gathered together, it is time to get everything put together. Make sure to put everything together in the location where you want to use it. Keep in mind, the rocket stove will create smoke and a lot of heat, so don’t set this up too close to the house or other flammable items. Also, the hot water heater needs to be somewhere convenient for regular use. Once you’ve chosen your spot, follow these instructions:
- Fit the copper coil inside of the stove pipe, as snugly as possible. Have one end coming out a small hole at the bottom of the stove pipe, and another as high up as the coil reaches. These holes can be made with a metal drill or a piercing tool.
- Place a Y connector on the emergency drain spout on the hot water heater. This is where you will get your hot water.
- Once securely inside, run the copper pipe over to the hot water heater’s drain spout. Hook the copper pipe up to one of the connections on the Y connector you just added, and open the spout. *at this point, the hot water heater is still empty. Make sure the second spout is still closed.
- Next, run the copper tubing that comes out of the top of the coil into the top of the hot water heater (where the cold water feed normally goes). Secure the pipe there.
- Fill the hot water heater with as much cold water as you need. This will go into the top of the hot water heater through into the hole where the hot water exits normally.
Your pump free, electricity free, gas free hot water system is now fully set up. When you need hot water, you simply have to start the fire in the rocket stove. It will take some experimentation to see how long it takes to heat up the water. It will be based on how much water you’re heating, how hot the fire is, and how long the copper coil is.
How it Works
This water heating system works using a thermo siphoning process. The cold water in the water heater will run through the copper pipe until it gets into the coil, where the pipe is extremely hot from the fire below. This is done through gravity at this point. Once the water gets to the pipe, however, it gets heated up, driving the water up through the rest of the coil, and then back out the pipe and into the top of the hot water heater. This hot water stays near the top of the water in the hot water heater’s tank.
As the hot water is pushed up through the pipe, it sucks more cold water in as well. This continues to cycle through, bringing the cold water out the bottom, and placing hot water into the top of the hot water heater. As the water cycles through, all the water in the tank keeps getting hotter and hotter, allowing it to run more efficiently. Keep in mind, there are no regulators or thermometers involved here, so if you let this system run too long, it could cause the hot water to burst out of the top, resulting in severe burns.
This system can easily heat the water to 180-200 degrees, which is much hotter than the typical hot water heater. With this in mind, be extra careful when using the water, or it could result in scalding. To heat 20 gallons of hot water, it will typically take about 30-40 minutes, once the fire in the rocket stove is going well.