Contents
Making a tankless water heater with your own hands is a great idea if you suffer from a lack of hot water in the summer or want to organize a shower in the country. You can make a protochnik yourself, because it is quite simply arranged. What you need to work and what steps to go through, you will learn in the article.
Flow heater device
We wrote in detail about how the boiler is arranged in the article “How to choose an instantaneous water heater».
We list the main nodes and consider the principle of operation. The body of the device is equipped with a flow heating element, which is placed in a protective flask, so it is practically not subject to scale. Water passes through the heater, reaching the optimum temperature. The advantage of such work is that you can get hot water at any time.
To create an electric water heater, the most important thing is to purchase a heating element. You have two options:
- Simple – buy a new item in the store. It is important to choose the right power: a conventional network will not withstand more than 5 kW, and for summer cottages it is better to take 3-4 kW.
- Make a homemade heating element.
What you need to make a heater:
- Spiral (TEN).
- Copper tube for the manufacture of a protective housing.
- Two ½ threaded steel tubes.
- Steel sheet 3 mm thick.
- Nichrome wire.
- Heat resistant adhesive.
- Anti-corrosion paint.
- Gas-burner.
- Apparatus for welding.
- Bulgarian.
- Drill.
- Metal brush.
- Sharp core.
- Electrodes.
- A hammer.
How to make a heating element yourself:
- Twist a spiral of copper tubing. Make at least three turns at a distance from each other.
Twisting the tube can cause it to buckle at the bends. To avoid this, we recommend filling the cavity with sand and closing the edges with plugs.
- Wind the wire tightly around the tube so that there are no gaps between the turns. Secure the ends with heat resistant glue.
- To obtain more power, the spirals are powered in parallel. With series power, heating will be worse.
- Then the element is placed in a copper tube and sealed.
To accurately manufacture an electrical device, you need to calculate the materials.
Calculation for the manufacture of direct-flow heating elements
It is necessary to calculate the dimensions of the future heater, how much wire and copper pipes are required.
How much wire do you need? To take a shower with normal pressure and hot water, the power must be at least 5 kW. From the calculations below you can see the current strength:
P=IxU; I=P/U=5000W/220V=23A
Therefore, take care of the normal wiring in the room in advance. It is better to use thick cable. Now calculate the indicators using the following formula:
R (maximum resistance is 1,1 ohm x mm²/m) = p (wire resistance) x L/S (sectional area).
How to find the cross-sectional area? Calculation method only:
S u3,14d πr² u0,5d 0,8xXNUMX² uXNUMXd XNUMX mm²
Wire length:
L= 8,8/1,4=6,2 m
Divide this number by the number of turns of the heater.
Let’s say the dimensions of the tube are 10 mm, and the thickness is 1 mm. With parallel winding of the wire, the distance between the turns should be 2 mm.
How to assemble a flow heater yourself
Before you start assembling, prepare all the parts. The metal must be cleaned of rust, for this a drill with a brush head is used. Keep in mind that the diameter of the sheet must exceed the dimensions of the heating element bulb.
Mark the places on the sheet where the spiral will be located. Use a drill with a bit larger than the heater foot. Make holes for mounting bolts. Make holes on the end of the product with a core. They should be located strictly in the middle.
Make two sketches with a grinder. Follow the diagram and markup. On the second option, holes are not needed. The result will be the lower and upper parts of the device. Then proceed like this:
- Connect the part with the holes and the flask of the heating element. Make sure that all connections are tight, then weld the parts to each other.
- Make sure that the length of the flask does not exceed the size of the spiral by more than 1,5 cm. Otherwise, you need to shorten it.
- Make two holes in the pipe for water supply, top and bottom.
- Weld the pieces of pipe so that the non-threaded side faces the bulb.
For mechanical heating to work, you need to regulate the temperature. Therefore, install a thermostat next to the heating element. It is better to install the start button on the surface of the tank.
- Weld two bodies that were cut from the sheet.
- Install a ground bolt inside the chamber.
- Connect the device to water and run to test.
- Inspect how tightly the parts are soldered, if there are any leaks.
- If everything is in order, you should turn off the device, prime and paint the surface with anti-corrosion paint.
If desired, you can organize gas or wood heating of water. But then it is better to make a storage-flow case.
A simple home-made device is not safe, so you need to constantly monitor its operation, control the flow of water so that the heating element does not work in vain. After all, this technique does not have protective sensors.