To choose a water heater for a house or apartment, you need to understand which type, instantaneous or storage, will suit you.
Which water heater is more profitable?
A flow-through water heater has such advantages as small dimensions and almost instantaneous heating of water. However, their installation requires a dedicated electric cable and a circuit breaker in the panel.
Therefore, instantaneous heaters with a capacity of more than 3.5 kilowatts cannot be installed in old high-rise buildings, but a storage one is quite suitable.
No matter how strange it may seem, instantaneous electric heaters in total require less costs. Initially, the cost of a flow-through heater is lower than that of a storage heater. You can also save on mixers - flow-through water heaters are often equipped with them. Another way to save is to use a separate heating device for each water intake point, this will allow you not to waste electricity on heating in the pipes between the taps.
It should also be remembered that the water in storage devices is heated more than once, and electricity is also used to maintain a constant temperature. With a small water consumption, this is not very profitable compared to a one-time heating in a flow-through heater.
It should be taken into account that the service life of flow-through devices is almost twice as long and is about 20 years. In addition, storage heaters also require proper maintenance.
How to determine the required power of the device?
To determine the required energy intensity of a water heater, you need to decide in what mode it will be used. For example, washing your hands requires a water flow of about 2-4 liters per minute, but taking a bath will require 8-10 liters per minute. When choosing a heating device, you must start from the point with the largest water intake. So, to fully provide an apartment or small house with hot water, it is necessary to take for calculations a water flow of at least 15-20 liters per minute.
Also, when choosing the power of a heating device, it is necessary to take into account the difference in voltage levels in the Russian Federation - 220 V and in Europe - 230 V. It is because of this that when connecting a heater with a declared power of 10 kW, manufactured in Europe, to our power grid the nominal indicator will be only 9.15 kilowatts.
If it is necessary to accurately calculate the power of the electric heater, then the digital value of the flow rate of liters per minute must be multiplied by the difference between the required temperature and the temperature at which the water enters the heater. Divide the result by a constant coefficient of 14.3.
If you liked it in the store instantaneous water heater, then look at the indicated value of its power. Based on this indicator, you can very easily determine how much water this device will produce per minute at a temperature of about 25-30 degrees. For example, a heating device with a power of 10 kW will supply the house with a water flow of 5 liters per minute. This is more than enough to wash your hands or wash your face.
You can also use the following list, which shows the approximate power required for daily needs:
- 4−6 kW - for washing and washing dishes;
- 6−8 kW – for using a shower;
- 10−15 kW – for using a sink and shower at the same time;
- 15−20 kW – for unlimited use in the apartment.
From the above values, we can conclude that for comfortable use, the power indicator of an instantaneous water heater must be at least 8 kilowatts.
Installation of devices with such power is possible only in old houses where the installation of electric stoves is provided or in houses of modern construction. But electric water heaters with a power of 12 kW or more are installed in individual houses. Therefore, heating devices are available for single-phase and three-phase networks, but single-phase electric heaters are usually not produced above 10 kW.
Pressure or non-pressure instantaneous water heater?
In addition to the energy intensity of the instantaneous water heater, you also need to decide whether a pressure or non-pressure device is needed specifically for your needs.
Pressure-type heaters, the so-called system ones, make it possible to obtain hot water from all taps in an apartment or house.
Such a water heater is mounted directly into the water supply pipes. This is certainly preferable if the central supply of warm water is turned off. Such a heater is activated automatically when pressure appears in the pipe, that is, when the user turns on the tap.
Non-pressure devices are produced with a power of no more than 8 kW. They are often immediately equipped with mixers, that is, they can serve a single water intake point.Such electric heaters are especially convenient to use during the summer season and in guest country houses.
Another advantage of such devices is their relatively low cost, so experts recommend installing your own heater for each water intake point. This is also beneficial from the point of view that there is no need to heat water in pipes, that is, electricity consumption is reduced. They are quite easy to install and remove, which is why they are preferred to be used in dachas.
What do you need to know before purchasing?
Instantaneous water heaters made in Sweden, Italy, Germany, Poland and Russia are widely represented on the modern market. You should choose a manufacturer based on cost and reviews.
When you have already decided on the required power of the electric water heater, before choosing a specific model, it would be useful to use the following tips:
- Go to your service organization and find out whether the electrical network of a particular house will allow you to connect an instantaneous water heater. You may be advised to use additional equipment to help you operate your heating appliance safely and reliably.
- It is necessary to find out how difficult it is to install the device, whether it can be done independently or is it better to contact specialists. Decide on the cost of the work itself and the materials that will be required for this.
- Ask about the reliability of the selected heater model, the terms of warranty service, how difficult the repair is and what the cost of spare parts is. It would also be useful to find out where the nearest service center is located. In case of breakdown, this will save your nerves and money.
- When choosing a gravity heater, it is worth remembering that to compensate for the lack of the required amount of water, small holes are made on the nozzles. If there are a large number of impurities in the water, they “clog” very quickly and this can result in overheating of the device. Therefore, such attachments must be systematically washed with anti-scale agents.
- Many low-pressure water heaters with low power are simply not intended for use in the cold season - they simply cannot heat the water to more than 25-30o C. Therefore, you can consider heaters that are made in countries with colder climates.
