An electric water heater is an undeniably useful thing, because it can provide hot water even where there is none. It will also help you save on hot water in the apartment. Now there are two types of heaters on the market, the first is a flow type, the second is a storage type. Many are inclined to the second type due to the fact that it can be included in a regular household network. But what size should you choose? After all, they are subdivided from 5 to 200 liters?
To calculate the volume you need, you first need to think - how many people will use this water heater? How many points of analysis it will be calculated for, whether there will be an installed bathroom or only a shower cabin, whether it will be used as the main source of water heating.
How many people will use
Here, as you understand, the consumption of water directly depends on the number of people. In order to calculate the required volume, you need to “estimate” how many liters you consume during an active period, for example, in the morning. The heater should be enough for 1 shower (not a bath), everyone for morning washing (brushing teeth), there should also be a small margin, 10 - 15%.
- For one person - 30 liters will be enough.
- For a family of two, it is worth considering an option from 50 liters.
- A large family - in any case, should take the 100 liter version.
Taking a bath should be planned in advance, as it will "empty" all the hot water and then you will have to wait about an hour or two for heating. Or immediately install titanium with a volume of 150 liters or more.
Below we have given 2 ways to calculate the volume of hot water for your needs.
Protection against bacteria and viruses
During the period of self-isolation, the presence of a water heater becomes vital, because constantly being at home or in the country (where you used to spend only weekends and did without a water heater), you use tap water of dubious quality every day.
At such a time, it is extremely important to take care of the purity of the water used daily in everyday life.
For example, coronavirus bacteria have already been found in mains water in Paris (this news has been repeatedly mentioned in the media). That is, using water from a well (in the country) or from a heating system (in the city), you are not protected from harmful bacteria and viruses.
In addition, many consumers notice that the water from the mains has recently begun to smell strongly of bleach. This, firstly, is very unpleasant, and secondly, it proves that they began to purify water more, which means there is something to be done. The question is - how is it cleaned, how harmful is it and how well does it purify water? No one will give you the exact answer.
1. A water heater is a device that heats water to 70-75 degrees, which allows you to get rid of vegetative forms of bacteria in the water and stop their reproduction. That is, using water prepared through heating in the tank - you get not only water at the temperature you need, but also CLEAN WATER for your SAFETY and PROTECTION from viruses and bacteria.
How is water disinfected and purified?
Heating water to 75 degrees kills germs, bacteria and the smell of bleach. Purification of the main water does not provide this, since many management companies simply save and underheat water, and the treatment components may not be able to cope with this.
Criterias of choice
To make the right choice, you need to consider the characteristics and features of the device:
- Power. The power depends on how quickly the water in the tank will heat up. Most often, you will be able to choose the intensity of water heating and temperature. This affects the heating time and power consumption. Do not forget about the possibilities of your wiring. Powerful models require thick wires and powerful machines.
- Spaciousness. Start from the number of consumers.The volume per 100 liters is enough for taking a shower and household needs of three people. If you are installing in the country, 80 liters will be enough there.
Tank quality. What material is it made from?
In order for the device you have chosen to serve for more than one year, you need to pay great attention to its quality and material of manufacture. Tap water negatively affects the boiler from the inside, so many manufacturers use steel and resort to coating the container with a protective compound.
When choosing a stainless steel tank, pay attention to the quality of the metal itself. The best steel grade is AISI 304. This design will last much longer.
Pay attention to the inner coating - ceramics and glass-ceramics protect the product well from corrosion. Finely dispersed enamel as a coating also does an excellent job of protecting a steel tank.
Also, the effect of tap water affects the heating element of the tank. There are wet and dry types of heating elements. The first option is in direct contact with water, as a result of which scale forms on it, it undergoes corrosion, which ultimately leads to a breakdown of the heating element. Therefore, a wet heating element requires regular repair and replacement, while a dry heating element is isolated from water and is more practical. The price of a boiler with a dry heating element is higher than the cost of its counterpart, but for installation in an apartment it is better to give preference to just such a boiler.
Thermal insulation quality
The most common layer is foam rubber. The latest models use polyurethane.
Anode - it must be in the design to protect the tank from corrosion and scale. Anodes are aluminum, magnesium (with increased mass) and titanium (electronic).
Protection. Special sensors that protect against water overheating, from turning on without water, a safety valve provide the device with a long service life.
How to choose a storage water heater by volume
To choose a storage water heater of the volume we need, we need to know the needs of our family for hot water.
The first way to calculate the volume of a storage water heater
The table below shows how much hot water per day is consumed by certain appliances for different numbers of people living:
We are talking only about hot water - from a hot tap, and not a mixture of "hot + cold = warm". The table is given for hot water with a temperature of 60 degrees.
Summing up the numbers from the column, we get the consumption of hot water per day for our family. So, according to the table, for a family of 4 people you need: 30 + 100 + 120 + 250 = 500 liters of hot water per day.
The second way to calculate the volume of the storage water heater
There is an even simpler way - from practice and observation: you need 110 liters of hot water per person per day; accordingly, we multiply 110 liters by the number of people living. For "our" family of 4: 110 * 4 = 440 liters of hot water per day.
In general, both methods can be used.
Attention! If you have a need for hot water, as in the example, is very significant - DO NOT be alarmed: after all, this is a DAILY need! But there are two peaks of hot water consumption: morning and evening (on weekdays). That is, part of this water is consumed in the morning, part in the evening, well, and some in the afternoon. So the entire volume can be divided by three, i.e. in the above example, the volume of the boiler needs two hundred liters or so.
Save on volume or not
According to statistics, a city dweller uses from 100 to 400 liters of water every day, most of which is hot.
Naturally, the consumption of water by each person is purely individual. One will be able to use the volume of the water heater to take a full bath, leaving some water for washing dishes or hands, but for another family member it will take a little time for the next portion of water to heat up.
But if you are not at all concerned about saving water and electricity consumption, and financial security and the potential of electrical networks allow you to use a powerful heater, in this situation, purchase several devices with capacitive tanks of 200-300 liters.
Water heaters from 150 liters are floor-standing, since the wall may not withstand a heavy load. Wall models can be installed vertically and horizontally.
Shape and location
To date, storage water heaters have various shapes: cylindrical, oval, square or flat. In addition, boilers are of horizontal and vertical type of arrangement. Please note that vertical models have a bottom-mounted nozzle, and in a horizontal position, the nozzles will be on the side. At the same time, modifications are possible with both left and right connections.
Separately, you can select models with a universal mounting method. The water heater can simply be turned on its side and hung as space permits. Tanks are designed in such a way that the functionality in both vertical and horizontal positions is not disturbed.
Also pay attention to the method of mounting the device. After all, not all walls are able to withstand water heaters, the volume of which is more than 80 liters.
For example, in the presence of foam concrete walls, it is better to choose a floor boiler model.
Therefore, before making the final choice of a water heater, you should carefully consider its future location, and based on this, choose the shape, location and mounting of the boiler.
Dimensions and form factor of storage water heaters
The volume of water that can be stored directly depends on the dimensions of the water heater. The heater with a capacity of 50 liters is much shorter in length than a similar model, but with a capacity of 100 liters. Typically, the tank diameter of most heaters does not exceed 45 centimeters.
With an increase in volume, only the height of the water heater increases. For a tank with a capacity of 50 liters, the height is 50-60 cm, with a volume of 80 liters, the height reaches 75-85 cm, 100 liters - up to 115 cm, and the height of a heater with a capacity of 150 liters reaches 160 cm.
Flat heaters
Inside the flat water heater there are 2 connected cylindrical tanks. They are just as reliable as the classic models. Moreover, modern models allow you to orient them in space as required by the design of the room or conditions. Vertically or horizontally.
Square water heaters
Usually, water heaters of small volume (6-30 l) have a square shape. They are very popular for installation in the kitchen of an apartment or cottage. At the same time, such a water heater has a round tank inside, and its diameter is from 30 cm. In fact, it is no different from conventional models, it differs only in design and a large amount of insulation. Since it's empty space, something needs to be filled.
Slim water heaters
Water heaters are produced with a circular section with a diameter of 38 cm. This type of heater is very reliable. They are widely used in applications where installation space is very limited. Installation is carried out in existing niches and various non-standard places. As already mentioned, with a decrease in thickness, the height of the heater increases. For example, a slim heater with a capacity of 50 liters has a height of 80 cm, 80 liters - 115 cm, 100 liters - reaches a height of 140 cm. Recently, manufacturers have gone further and UltraSlim models are becoming popular. You can mount it in a very limited space, and the fact that this water heater can be mounted both horizontally and vertically gives even more mounting options - for example, horizontally under the ceiling, using a flexible connection.
Flow type water heaters
In total, there are two types of flow heaters on the market - pressure and non-pressure. Pressureless heaters have low energy consumption and are able to heat water at two points if they are located nearby (for example, kitchen and bathroom). For a long service life, it is necessary that the water heater (dimensions do not matter) be installed in accordance with all installation rules. This is due to the fact that the pressure in such a device is equal to atmospheric. Therefore, when the boiler is on, the tap must be open. Otherwise, such a heater will not last long, and in the worst case, it will explode and cause damage not only to the room, but also to people.
Pressure devices are another type of instantaneous water heaters - they differ in that they work under pressure. Thanks to this, they are convenient to use - just turn the mixer knob. They are of two types - with a hydraulic control system and an electronic system. More comfortable is a water heater with automatic electronic control. This system not only automatically turns on and off the device, but also maintains the temperature at a constant level, which completely eliminates human intervention in this process.
The novelties of recent years - instantaneous water heaters in the form of taps - are pressure devices that consume only 3 kW and are easily installed instead of a standard mixer in two steps - we connect the cold water inlet, then the device is plugged in - and you can use it.
There are also indirect water heaters
An indirect boiler does not differ much from a conventional water heater. From the outside, it's a nice tank. It may be quite a solid size, it all depends on its volume. The boiler consists of: (a body, a certain insulation, a main durable, stainless tank, a thermometer, a heat exchanger - a coil and a magnesium anode).
The insulation layer, located between the body and the main tank, is a powerful thermos, due to which the system has practically no heat loss - (2-3 ° C) in 24 hours. The process of monitoring and controlling the temperature regime allows you to constantly maintain the specified temperature parameters of hot water.
Separately, it is worth dwelling on the device of the heat exchanger. It is a spiral of a special design made of a hollow tube (metal or brass) installed in a special way (usually in the lower part inside the case). The location of the coolant is of fundamental importance for optimal water heating. When heated, water changes its density, and warmer water rises to the top of the tank. This arrangement of the coolant allows you to quickly and evenly heat large volumes of water.
Advantages and disadvantages
The strong qualities of indirect water heaters can be safely considered:
- Significant volumes of hot water and uninterrupted supply of hot, not warm water.
- Simultaneous provision of several sources of hot water consumption of the required temperature.
- During the heated period of the year, the cost of heated water is the lowest in terms of costs. Since heating occurs due to the heat already received from another carrier (heating system).
- Water heating, unlike flow heaters, occurs without an inert delay. Opened the faucet and hot water came out.
- Depending on the availability of heat sources, several energy options can be applied, including solar energy.
Weaknesses include:
- Additional financial investments are required. The water boiler works in conjunction with other equipment.
- It will take a long time for the boiler to heat up initially. During this heating period, the heating temperature of the house may decrease.
- The boiler must be installed in the same room as the heating system.The volume of the room should provide a complete installation of both the heating system and the boiler.
Advantages and disadvantages of an indirect heating boiler
The indirect heating boiler is operated in tandem with a single-circuit boiler. Therefore, the unit takes up more space than the installed double-circuit boiler. But using the principle of indirect heating allows you to always have a sufficient amount of hot water at the right temperature.
If hot water, heated directly, is consumed from several taps at once, its pressure begins to drop. The operating mode of the boiler is changed. When draining hot water from different taps at the same time when the direct heater is operating, the water temperature decreases. If cold water from another tap is used in parallel, the flow through the direct heat exchanger is reduced. Due to this, the water temperature becomes higher than necessary.
Wiring diagram for an indirect heating boiler
The boiler serves several water intake points, providing stable water parameters. Its consumption is limited only by the capacity of the unit. It is convenient for frequent interruptions in water supply and power supply. When the tap is opened, hot water flows immediately without prior draining, which is typical for instantaneous water heaters.
If indirect heating is used in the installed boiler, please note that hot water supply is only possible during the heating season. In the summer, it is necessary to periodically turn on the boiler or switch to an alternative source of heat carrier seasonally. The disadvantage of using this type of unit is the inertia of its operation - it takes a long time to heat a large volume of water.
A gas or solid fuel boiler, a centralized heating system, solar panels or a heat pump can serve as a source for heating the coolant. Models are produced with two heat exchangers to use different heat sources.
