Contents
Today we will talk about instantaneous water heaters and give useful tips on choosing them.
Comfort first and foremost
It is difficult to imagine now a comfortable home without hot water. After all, it is one of the components of the amenities in the house.
The first hot water that people began to use were natural thermal springs. Then he began to use an open fire to heat water.
Later, heaters appeared, the water in which was heated by burning solid fuel.
Now the most common are heaters, where gas and electricity are used as a source.
A feature of heaters with such heat sources that provide water heating is the use of two types – storage-type heaters and flow-type heaters.
At home, electric water heaters are becoming more and more popular.
Now many houses are being built without connecting it to the gas main, and all the amenities in the house are provided with electricity.
Such water heaters are also relevant for owners of houses and summer cottages, to which it is impossible to conduct gas.
Well, it is worth recalling that in many cities their residents only dream of a centralized supply of hot water and, probably, these dreams are unlikely to come true. Although hope dies last.
In general, where it is not possible to use gas to heat water or there is no centralized hot water supply, electricity is used to heat cold water.
Types of electric water heaters
In both storage and instantaneous water heaters, the main element for heating water is TEN. It’s just that they heat differently.
At storage water heaters, water enters a special container, inside of which is located TEN.
With the help of an adjustable thermostat, the temperature to which the TEN must heat the water is set.
Having brought to the desired temperature, the TEN turns off, but with a slight drop in temperature, it turns on again and brings the temperature to the desired value. This keeps the water warm at all times.
With a partial flow of water, a new portion of cold water enters the tank from the water supply system to the level, and it is heated again.
How to connect a storage water heater – diagrams.
Instantaneous water heaters do not have a water tank. Water entering the water heater passes through the supply pipe.
A housing with a heating element is fixed on this branch pipe. Water, passing through the pipe inside the housing, is heated, and goes to the consumer through the outlet pipe.
Advantages and disadvantages of instantaneous water heater
Instantaneous water heaters have a number of positive qualities:
- The absence of a water tank makes it very compact, and since this heater has a stylish outer casing, it fits perfectly into the interior;
- The instantaneous water heater provides almost immediately the supply of hot water after it is connected to the network. Because of this, it is convenient to use them in country houses and cottages;
- You can choose heaters of different power, capable of delivering hot water both to one point and to several.
The disadvantage of this type of water heater is only one – in order to ensure rapid heating of the water flowing through it, it must have good power, which affects its energy consumption.
See also:
Types of instantaneous water heaters
Now two types of instantaneous water heaters are produced – non-pressure and pressure.
Non-pressure instantaneous water heaters can be connected to almost any source of cold water, but the main thing is that this source has a tap to shut off the water supply.
Below is the Electrolux SMARTFIX 3,5 S model.
In order for such a water heater to start working, it is enough to turn it on, set the water temperature and open its supply on the tap.
The heater itself will continue to operate on the flow of water, that is, if you shut off its supply, it will automatically turn off.
Due to this feature, these water heaters are unable to provide hot water to several points of intake.
But since they work only for one point, their power is relatively small – from 3 to 8 kW.
Pressure water heaters are included in the water supply system of the house. That is, the water in it is constantly under pressure.
But as long as all the taps in the house are closed and water is not consumed, it does not work.
Below is the Stiebel Eltron DHF 13 C compact model.
As soon as one of the taps opens and a stream of water appears through the heater, it starts working.
Such a water heater is capable of operating at several points of intake. However, to ensure the heating of a large amount of water, it must have a large power – up to 36 kW.
Schematic diagram of the installation of a pressurized instantaneous water heater.
Design
Structurally, both of these types of instantaneous water heaters are similar. All their elements are enclosed in a case.
On the one hand, there are two branch pipes – for supplying water to the heater and exiting it.
There is also a wiring with a plug to connect it to the network. On the outer part of the housing there is a control unit that sets the temperature and operation mode of the heater.
Inside, there are pipes through which water moves inside the water heater, these pipes pass through a copper flask with heating elements located in it, and where it is directly heated.
Also included are fuses, a temperature stabilizer, a power regulator, a thermal cycling interrupter and a flow regulator.
Pressureless water heaters, since they can only provide one point of intake, may come with shower heads or sinks.
That is, it is enough to connect a pipeline with water to it, and on the other hand, a nozzle directly onto the outlet pipe and the water heater is ready for use.
This allows you to use it as a portable one – installed in one place and used, the loan was transferred to another.
Pressure ones are included in the water supply system.
In principle, it can be included in this system and used only in certain cases, for example, when hot water is turned off from the central water supply.
At the same time, they can provide hot water to the whole house.
Selecting a flow heater
Having decided to install an instantaneous water heater, you should decide on some features.
So, first you need to decide whether the electrical network at home can withstand such a load.
And also you need to decide on the purpose of using an instantaneous water heater.
Below is a table, after studying which you can draw certain conclusions for yourself.
In old houses, where the wiring is not designed for heavy loads, it will not work to install an instantaneous water heater. Although it is still possible to install a low-power water heater of 3 kW, it is better to check the network before purchasing by connecting a consumer with the same power to it.
In modern houses where an electric stove is used, there is not much need to check the network, if it can withstand the stove, then it will also withstand the heater.
Based on this, the type of water heater is determined. If the network is weak, only a non-pressure water heater should be purchased.
Some owners, if several hot water supply points are needed, purchase several non-pressure heaters, and thereby solve this problem.
Determination of the required power
Next, the required capacity of the water heater is determined in order to provide the required amount of hot water.
This indicator is actually calculated according to a certain formula, including the need to determine the flow of water, the temperature of the water supplied to the heater and the outlet temperature.
However, it is possible to calculate the power of the water heater much easier.
It is enough to divide the power of the device in two, the result obtained is the volume of running water heated by it to 20-30 degrees. in a minute.
That is, a 20 kW water heater will heat 10 liters of water per minute to 20-30 degrees. Based on this, it is already determined what the approximate water consumption will be, and what heater power is needed for this.
If a water heater is purchased that will provide several water intake points, then the power is determined by the point with the highest water consumption.
There is a possibility that water intake will be carried out at several points at the same time, then the result of calculations for the maximum flow rate from one point should be increased by one and a half times.
Other features when choosing
Before purchasing, you should immediately determine the installation location of the water heater, especially for the pressure type.
It is better to place it as close as possible to the electricity meter.
The schematic diagram is presented below.
It is also advisable to install a circuit breaker in front of the outlet from which it will be powered, which allows you to protect the house network from unwanted overloads from the operation of the water heater, and the device itself from power surges.
The last criterion when choosing is the convenience of its management.
Inexpensive options are equipped only with a power button and a manual temperature selector.
More expensive ones may already be equipped with a temperature display and touch controls. But this is a matter of taste and availability of finance.