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Instantaneously get hot water at the outlet of the tap allow instantaneous water heaters. Devices are used in apartments, cottages, production, in general, wherever there is running water and electricity. There are also water heaters that run on natural gas. However, such models cannot be installed independently without a representative of the gas company and the execution of relevant documents. Now we will talk about choosing an electric instantaneous water heater for a shower in the country, as this device is the best option for obtaining hot water without any problems.
Requirements for electric instantaneous water heaters
Manufacturers offer many models of instantaneous water heaters. All of them differ in power, water throughput, heating element design, equipment, etc. The only thing in common in these devices is that they are all powerful and require connection only to a reliable power supply.
If you choose a shower water heater, then the optimal model is with a water flow rate on the watering can within 6 l / min. When using the shower in winter, you need more power of the device. At this time of the year, the water temperature in the main line is about +5оC. To heat it for bathing in the shower, you will need a pressurized water heater with a capacity of 13 kW or more. A single-phase network will not cope with this, and a connection to a three-phase line will be required.
Not every owner of an apartment or cottage can boast of having a 380-volt network, so non-pressure water heaters are the best option for domestic needs. The power of such devices is from 3 to 8 kW, and they work without problems from a single-phase network. When choosing a water heater for a dacha for a shower, it is better to give preference to a model with its own nozzle-watering can.
Before buying an instantaneous water heater, you need to find out:
- what is the maximum load the home electrical network can withstand;
- is it possible to carry out a three-phase network in an apartment or in a country house;
- for which model of the water heater the parameters of the water supply are suitable (constant pressure in the line is taken into account).
In the apartments of modern houses, you can put an electric boiler of any power, even a pressure model of a water heater. According to existing standards in new buildings, the power grid is designed to connect equipment with a capacity of up to 36 kW. For giving in the shower, only a non-pressure device with a power of up to 8 kW is suitable.
How an instantaneous water heater works
In storage water heaters, water is heated inside the tank from an electric heating element. Flow type devices are similarly equipped with a spiral or heating element, only they heat the liquid during its movement. Despite the high power of the electric heater, flow models are sometimes more profitable to use than storage counterparts. The fact is that the heating element consumes electricity when water is being parsed. In the storage tank, the heater periodically turns on around the clock, even if there is no water analysis.
The heart of the flow device is a hydraulic relay. From it comes the command to turn on or off the heating element, which depends on the speed of the water flow. The hydraulic relay is adjusted to operate at a water flow rate of 2 to 2,5 l/min. If this value is less, no heating takes place. This function protects the device from burnout of the heating element.
Any instantaneous water heaters powered by electricity are divided into two types:
- Electronic models heat water to the specified parameters, regardless of its initial temperature, flow rate and pressure in the pipeline. Water is heated by changing the power of the heating element.
- For hydraulic models, the power of the heating element depends on the listed parameters. With an increase in water consumption, its temperature at the outlet of the tap will decrease.
All these subtleties of the device of instantaneous water heaters must be taken into account when choosing the optimal model for the shower.
We calculate the power of instantaneous water heater
Professionals use complex formulas for calculating the optimal power of the device. At home, in order to choose a suitable model for the shower, we perform the simplest calculation:
- The first step is to determine the approximate water flow at the draw-off point where the heater is supposed to be installed. At the beginning of the article, we already found out that the optimal flow rate for a shower is 6 l / min. For reference, the flow rate at other water points: washbasin – 4 l / min, bathroom – 10 l / min, sink in the kitchen – 5 l / min.
- Next, we use the formula for calculating the power of an electrical appliance P = QT / 14,3. Instead of Q, we substitute the value of the water flow. T is an indicator of the temperature difference, which is in the range of 30–40оC.
You can go in the calculations on another simple way. It consists in multiplying the value of water consumption by the number 2 or 2,5.
Pressure and non-pressure models
Initially, we touched a little on the topic of pressure and non-pressure water heaters. Now it’s time to take a closer look at them. Since a non-pressure model is suitable for a shower in the country, we will start with it.
Non-pressure type devices at the inlet are equipped with a shut-off device that neutralizes the excess pressure of the water supply network. The water pressure inside the water heater is similar to atmospheric pressure. At the outlet of the device, it is not allowed to install any locking mechanism that interferes with the free flow of water. The heating of the moving fluid occurs even with pressure drops in the plumbing system, but if it reaches a critical level, the heater is turned off.
Non-pressure shower models are equipped with a watering can connected via a flexible hose. Moreover, the device of the watering can is slightly different from the analogues used in traditional shower systems. Special small holes create strong jets of water, even if the pressure in the water supply is below normal.
The main advantage of non-pressure type devices is the ability to connect to a home two-phase network. In the country, the device can be installed not only in the shower, but also in the kitchen. In apartments, non-pressure water heaters are rarely used due to their low power.
Pressure water heaters work on a different principle. Devices at the inlet and outlet do not have locking devices. Installation takes place by tapping into the water supply. Typically, a pressure heater is installed in front of a sink, bathtub or washbasin faucet. It is allowed to install the device on several water points. The main thing is that the plumbing allows this to be done.
Pressure water heaters are very powerful, due to which they manage to heat a large amount of water. An electronic on/off system and overheating protection controls the entire operation of the appliance. At the outlet, the water is always maintained at the set temperature.
A few tips for using instantaneous water heaters
So, we decided on the instantaneous water heater model, now we need to find out how to use it. The product should come with instructions, but a few additional tips from experts will not hurt.
When choosing a mounting location for a flow device, the following nuances are taken into account:
- It must be remembered that the device is powered by electricity and for safety it must be protected from splashing water. At the same time, it should be as close as possible to the shower stall.
- If the device is designed for different modes of operation, it is hung so that it is convenient to get it by hand for switching.
- The optimal installation site is the area where it is easiest to connect the device to the water supply and the mains.
In most regions of our country, the water is hard. During heating, solid accumulations form on the walls of the device and the heating element, which reduce the throughput. Installing a filter in front of the water heater will help to avoid this problem. Otherwise, the device will have to be periodically removed for cleaning, if its design allows it.
Recommendations for choosing an instantaneous water heater
An electric water heater must 100% cope with the task. So that the purchased device does not disappoint you, we suggest that you familiarize yourself with a few tips for choosing a model:
- When using a shower in the country, only in the warm season, the power of an electrical appliance of 3,5 kW is sufficient. Subject to water intake at a temperature of 18оWith the output, you will get a hot liquid with a flow rate of 3 l / min. For bathing in the shower with the onset of cold weather, it is optimal to purchase a water heater with a power of 5 kW or more.
- When choosing an electrical appliance, it is necessary to evaluate the stability of the water pressure. Otherwise, everything will end with a quick breakdown, or the water, in general, will not heat up.
- It is important to immediately determine how many water points the device is designed for. If they are far apart, it is wiser to buy several devices of lower power. They are installed directly next to the tapping point.
- In the shower in the country, choose models with the highest degree of electrical safety. In any case, at least a little splash will fall on it, and during the adjustment you will have to take it with wet hands.
In last place is the price of the product, because you cannot save on your own safety by buying devices of unknown origin.
The video talks about choosing a water heater:
Having decided to independently install the water heater, you must familiarize yourself with the elementary rules of electrical safety, and use the device only in accordance with the manufacturer’s recommendations.