A boiler is an indispensable device for homes that are not connected to a centralized hot water supply system. The variety of products on the market makes it difficult for buyers to choose.
The differences lie in appearance, heating method and other technical parameters. Experts recommend paying attention to the volume and power of the water heater.
Calculation formulas
To calculate how much energy a boiler consumes, you should take into account its volume, the time it takes to heat water and the power of heating elements. You can see all this data in your passport, but when choosing on the Internet, there is no such option. Therefore, the easiest way is to calculate the consumption yourself.
To calculate the water heating time, we use the formula: time = 0.00116 * volume (hot water temperature - tap water temperature) / power. From here it is easy to calculate how much electricity will be spent on this by multiplying the operating time by the power of the heating element.
Taking an average family of three, which consumes about 200 liters per day, we calculate the estimated energy consumption per day by dividing 200 by the volume and multiplying by the electricity for one tank. Multiplying the resulting value by 30, we get the number of kilowatts that will be required per month to maintain the hot water supply. The cost of maintaining heat in the standby state can be ignored because it is minimal.
Boiler power
Boiler heating element
This parameter is considered one of the main ones when choosing an electric heater - the normal operation of the electrical network in the apartment depends on the power, since not every wiring is capable of supporting devices with high voltage. The speed of heating water to the specified temperature also depends on this.
The performance of the boiler is determined by the heating element, which ensures that the device performs its main function. The principle of its operation can be compared to an electric kettle: the more powerful the heating element, the faster the water will reach the set temperature.
The performance of the water heater ranges from 1.5-27 kW and depends on its type. They are:
- flow-through;
- accumulative;
- combined.
The latter type is suitable for houses and apartments with an individual heating system, since during operation of a heating system based on a single-circuit boiler, the water in the combined appliance will be heated without connecting to the electrical network. The rest of the year it works from a wall outlet.
To choose the right boiler, you need to take into account the most frequently used water intake points. So, for washing dishes you need a heating element of 6-8 kW, for a shower - 12-16 kW.
Protochny
Instantaneous boiler
Instantaneous water heaters are distinguished by their compact size and instant heating of water. This is ensured by direct contact of the liquid from the water supply with the heating element.
Such devices are often placed in apartments where there are interruptions in the hot water supply or where there is no hot water supply. To use a warm stream in several places, for example in the shower and in the kitchen, you need to choose a boiler with the appropriate performance.
The power of flow heaters varies from 3 to 27 kW. Boilers with a power of 3-8 kW are capable of heating up to 6 liters of water per minute, which completely covers the needs of a family of 3-4 people.
However, it should be taken into account that in a standard apartment with a single-phase voltage of 220 V it is impossible to install equipment with a power of more than 5 kW - the wiring will not withstand it.
If we are talking about a private house, where the power supply reaches 380 V, then you can purchase more powerful models.
Cumulative
Storage boiler
Storage devices are large in size, as they contain a tank for storing heated liquid. The principle of its operation is as follows:
- The boiler fills the tank, turns on the heating and turns off automatically after reaching the set temperature.
- When you open the tap, hot water flows into the faucet or diffuser in the shower.
- As the container empties, it is refilled with cold liquid and the boiler is turned on again to heat it up.
The main disadvantage of storage water heaters is the long wait for the liquid to heat up. The speed depends on the power of the device and the volume of the tank.
The average boiler, which is suitable for any apartment, consumes from 1.5 to 3 kW. With this performance, 30 liters of water will heat up in 1-1.5 hours, and 120 liters in 4 hours.
Characteristics of boilers with a capacity of 50 liters
Let's take three 50-liter devices with different parameters and calculate their effectiveness. For everyone, let’s assume the temperature of the tap water is 15 degrees, and the hot water is 60 degrees. Daily consumption will be 200 l.
The Ariston ABS VLS EVO PW 50 water heater has two heating elements of 2500 watts. The heating time for a full container is 0.00116*50*(60-15)/2.5 = 0.928 hours, which is about 55 minutes. Daily consumption will be equal to 200/50*0.928*2.5 = 9.28 kW per day. This is 278.4 kW per month.
Boiler Ariston ABS VLS EVO PW 50
Electrolux EWH 50 Centurio DL is equipped with two heating elements of 1 kW each. All water is heated in 0.00116*50*(60-15)/2 = 1.3 hours, which is approximately what is written in the characteristics of the device. Per day this is 200/50*1.3*2 = 10.4 kW, 312 kW per month.
Boiler Electrolux EWH 50 Centurio DL
Ariston ECOFIX 50V 1.2 K is equipped with a 1.2 kW tubular electric heater. Time for heating is 0.00116*50*(60-15)/1.2 = 2.17 hours. 200/50*2.17*1.2 = 10.4 kW will be collected per day, 312.4 kW per month.
Boiler Ariston ECOFIX 50V 1.2 K
Consumption
Water heater
Electricity costs depend on how much electricity your water heater consumes. There are three types of heating technology and each option has its own characteristics:
- Storage water heater. It is a tank of different volumes, with a heating element inside. The water is heated to a certain temperature, after which the heater turns off. The process is monitored by a special sensor. When the temperature drops below the set value, the heating element turns on again and brings the temperature to the required one. This leads to excessive consumption of electricity if the heated water is not used in time and the device is not turned off. The range of electric heaters with heating elements is quite extensive.
- Instantaneous water heater. The device does not have a tank. Water moves through the pipes and enters the heater. Passing through it, the water reaches the required temperature. How much such a water heater consumes will depend on the inlet water temperature.
- Indirect water heater. The water in the tank is heated by the heating system. This could be central heating or a gas boiler. Thanks to the functional features of the boiler, the water in the heater remains hot for a long time, even after the main heat source is turned off. Thanks to the additional thermal insulation system, the volumes consumed by the indirect heating boiler are very small: due to the indirect use of electricity, significant cost savings are noted.
Through calculations and observations, it was found that flow-type devices consume more electricity because they have more power. But on the other hand, flow systems are turned on periodically, while storage systems are used constantly. The power of storage water heaters varies, so they cannot be called completely energy-saving.
Do not spend a lot and choose the right heating device, perhaps if you find out how much energy the boiler consumes per day.
To make calculations, you need to know the following indicators: the capacity of the water heater, the power of the device, water consumption, the time required to heat the water to the desired temperature and the energy consumption of the device in watts.
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There are approximate tables that allow you to estimate how much tank volume is required for comfortable use. For example, it is enough for one person to install a water heater with a volume of ten to thirty liters, while the first number is the minimum volume, the last is normal. For a family of two people, you need a fifty-liter boiler. A classic family of two adults and two children needs a water heater with a capacity of one hundred to one hundred and twenty liters.
Experts recommend an average of fifty liters of water per person per day. It's worth noting that the numbers could be much lower or higher. It all depends on the needs for using water: cooking, personal hygiene, laundry, washing dishes, taking a bath or shower. There are established standards for water consumption per person: about eighty liters are needed per day for washing, about twenty liters for washing dishes, about one hundred and eighty liters for bathing.
But when purchasing, not only displacement is taken into account. Since cold and hot water are mixed, the flow rate is lower.
Comparison of models with a volume of 80 liters
Let's take the daily norm as 250 liters, which is enough for 4 people.
Ariston 80V 1.2 K for 80 liters with a 1200 W heating element heats the full container in 0.00116 * 80 * (60-15)/1.2 = 3.48 hours. 250/80 * 3.48 * 1 are consumed per day ,2 = 13.05 kW, which will be 391.5 kW per month.
Boiler Ariston 80V 1.2 K
Electrolux EWH 80 Formax DL has two 2000 W heating elements. The entire container heats up in 0.00116*80*(60-15)/2 = 2.088 hours. 250/80 * 2,088 * 2 = 13.05 kW are consumed per day, in 30 days the result is also 391.5 kilowatts.
Boiler Electrolux EWH 80 Formax DL
Gorenje FTG 80 SM with two tubular heaters with a total power of 2600 watts. Water heats up in 0.00116*80*(60-15)/2.6 = 1.6 hours. 250/80*1.6*2.6 = 13 kW are consumed per day, 390 per month.
Boiler Gorenje FTG 80 SM
Calculation of the consumed amount of hot water per day
The cost, size and power of the boiler depend on this indicator. For a family with one child, at least 25 liters are consumed per day. This indicator includes: washing dishes and hands, hand washing and a light shower. If there are two children in a family, up to 250 liters are consumed per day. This may include: taking a bath, operating the washing machine, as well as wet cleaning. Such calculations are approximate, as they are based on customer reviews. The exact data can be found by installing a meter. The total figure should be divided by the number of days. This will give you the water consumption per day. Therefore, it is possible to determine which boiler is the most economical.
Let's consider an example of calculating the consumption of hot water for three people. On average, a family consumes about 70 liters of water per day. The temperature in the boiler can heat up to 90 degrees, and in the central water supply - up to 60 degrees. Thus, the hot water in the boiler mixes with cold water and produces more warm water than necessary. Therefore, it is recommended to buy a boiler with a volume of 40-50 liters.
Parameters of hundred-liter water heaters
We take a consumption of 300 liters per day, which is suitable for 5-6 living people.
The GBF 100 T/V9 100 liter burner has 1400 W heaters. Heating time 0.00116*100*(60-15)/1.4 = 3.7 hours. It will consume 300/100 * 3.7 * 1.4 = 15 kW per day, in 30 days 466.2 kW.
Boiler Gorenje GBF 100 T/V9
Bosch Tronic 1000 T ES 100-5 2000W BO L1X-NTWVB at 2000 watts will heat water in 0.00116*100*(60-15)/2 = 2.61 hours. 300/100 * 2.61 * 2 = 15.6 kW will be required per day, 469.8 kW per month.
Boiler Bosch Tronic 1000 T ES 100-5 2000W BO L1X-NTWVB
Atlantic O'PRO TURBO VM 100 D400-2-B at 2500 watts will heat all the liquid the fastest - in 0.00116*100*(60-15)/2.5 = 2.088 hours. It will consume 300/100 * 2.088 * 2.5 = 21.6 kW per day, and 648 kW will accumulate in 30 days.
Boiler Atlantic O'PRO TURBO VM 100 D400-2-B
You should also take into account the availability of a night rate. It may be more profitable to heat a lot of water at night and then use it throughout the day. In winter, the temperature of the water supply is much lower, which increases the heating time.
We can conclude that models with different parameters consume approximately the same electricity reading. At the same time, the price of powerful devices can be several times higher, which is explained by practicality - heating is faster.
Is it cheaper or more expensive to use a speaker?
An average geyser with the wick always on consumes 0.6-0.8 m3 of gas. Thus, 22-24 m3 of gas comes out per month, which even at the Moscow tariff for 2022 (5.7 rubles for houses with central heating and a water heater - for example, “Khrushchev”, “gostinok” and “small family”) is only 136.8 rubles.
And this is the consumption with a constantly running column. Meanwhile, in reality, of course, no one keeps it on 24/7. It is either lit with a match immediately before using the water and then extinguished, or turns on and off automatically. So if you really want to save money, buy not a boiler, but an automatic gas water heater - for example, like this one:
Is a tankless water heater profitable?
Instantaneous water heaters are most often used to heat water in country houses. Such equipment is easy to install yourself. The main disadvantage of instantaneous water heaters is their short service life - 5 years.
The water heats up as water enters. The power of the device does not depend on water pressure. Typically, a water heater provides warm water that you can use to wash dishes or take an outdoor shower. Due to some features, such a device is not suitable for taking a bath. It is recommended to install an electrical plug, socket and separate electrical cable. This is necessary in order not to reboot the main network.
A instantaneous water heater can have a power of 3-27 kW. For two people, a 10 kW device is suitable. For a large family, it is better to choose a water heater with a capacity of 20 to 25 kW.
Before purchasing, you should read the instructions, since some water heaters require a voltage of 380 V. If you nevertheless decide to connect the device to a 220 V network, then the electrical plugs in the meter will be knocked out.
The instantaneous water heater must be grounded, as it is installed on a metal mixer.
How does it affect work and energy consumption?
How much electricity an electric stove takes depends primarily on its type: it can be classic or induction. Secondly, this is influenced by the number of functions that are built into the stove and, finally, by the type of heating elements used in it.
To calculate the electricity consumption of a stove, two quantities are needed: the power of the heating elements and the duration of their operation.
Classic electric stoves using conventional heating elements (tubular electric heaters), for example, with a power of 1 kW consume 1 kW x 30 minutes = 300 kWh in half an hour. Knowing that kWh prices vary in different Russian regions, you can take the average cost as 4 rubles. This means that it turns out 0.5 kWh x 4 rubles. = 2 rub. This is the price for operating the stove for a quarter of an hour.
By testing you can also find out the amount of electricity consumed by an induction electric stove: taking, for example, a heating element with 1 kW of power, in a quarter of an hour of operation such an electric stove will consume electricity in the same amount as a classic one, but induction stoves have a big advantage - their efficiency 90%. It is so large because there is no leakage of heat flow (almost all of it is usefully used). This significantly reduces the operating time of the electric stove. Another advantage is that the burners automatically switch off as soon as the cookware is removed from them.
Some manufacturers focus on the production of combined stoves, which combine induction heating burners with heating elements in their design
For such stoves, when calculating power, special attention must be paid to the technical documentation, since the power of different types of heating elements can vary significantly
Of course, an electric stove is one of the most voracious consumers of electricity in an apartment. Typically, its energy consumption depends on the number of burners - their power ranges from 500 to 3500 W. Using simple calculations, you can obtain a consumption of 500-3500 W of electricity per hour per burner. Experience shows that in 24 hours an average family spends about 3 kW, which in a month will amount to 30-31 kW. This value, however, can increase to 9 kW, but this is at maximum load on the stove, for example, on holidays.
The energy consumption of a stove depends not so much on its properties, but on how it is used. Tips include information on ways to save money.
- As a rule, it is not necessary to use the highest heat setting when cooking. It is quite enough to bring the contents of the pan to a boil and then reduce the temperature level to the minimum. In any case, it will not be possible to heat food above 100°C, and the energy constantly released for boiling will lead to the liquid constantly evaporating. It has been experimentally proven that in this case you will have to pay for an additional 500-600 W of electricity for each liter of liquid (if the pan lid is open).
- It is advisable to cook food that requires a long time to cook on small-diameter burners with a minimum level of electricity consumption. In general, using this tip can save you a huge amount of money. It is for this reason that today almost every electric stove burner is equipped with a special temperature level regulator, which allows you to reduce energy costs by 1/5. To a large extent this applies to the so-called stepless type regulators, which allow you to increase/decrease the power level of the heating elements from 5% to a maximum. There are also stoves where the built-in equipment automatically controls the power level depending on how hot the bottom of the cookware on the burner is.
- When operating an electric stove, it is recommended to use special dishes that have a thick bottom that is as close as possible to the working surface of the stove. This improves heat transfer to the cookware.
A note on water heating efficiency
There is a common misconception that electric water heaters have an efficiency of 100%. This is due to the fact that in theoretical calculations energy losses are often neglected due to their small magnitude. But when calculations have practical application, it is easy to notice that in reality, energy losses when heating water occur from the first seconds. Depending on the heating device, these may be the following types of losses:
- to warm up the heating element itself (electric stove),
- to heat the walls of the container (kettle, tank),
- losses due to vaporization during boiling,
- heat transfer and thermal radiation of energy into the environment (from the walls of the vessel and/or heating element),
- evaporation from the surface of water in open containers (kettles and pans without lids),
- losses in electrical wires and contacts (heating of the wires and plug of the electrical appliance).
Additional minor losses include:
- losses due to side electrochemical processes (ionic heaters),
- sound losses (noise produced by steam bubbles at the point of contact of the heater or hot surface with water).
Based on the directions of losses, it is not difficult to determine measures to increase the efficiency of the water heating process:
- use of an immersion heating element,
- using a closed container,
- thermal insulation of the container,
- using the minimum required heating temperature.
How to save on a water heater: how many kW does a water heater consume per month
In the matter of saving electricity, one cannot do without making calculations and drawing up an approximate schedule of daily consumption. For storage systems, the following is taken into account:
- Heating tank volume;
- Passport data of the power consumption of the heating element;
- Heating time to the set temperature;
- The temperature of the supplied water from the water supply system.
For modern boiler models, electricity consumption is indicated in the passport data
For modern boiler models, electricity consumption, depending on the set heating temperature, is indicated in the device data sheet, while manufacturers take into account the maximum daily hot water consumption.
To calculate the total energy consumed by flow devices, the following is taken into account:
- Device performance;
- Operating time in a daily cycle;
- Temperature of heated water;
- Cold water supply temperature.
It is worth noting that modern models with intelligent control systems are not only more economical compared to models 5-7 years ago, but also make it possible to maximally meet all household needs for hot water, depending on the consumption cycle. This applies equally to boilers with heating tanks and instantaneous heating devices.
A properly organized daily cycle of hot water consumption and setting the correct settings for the heating element will help you save the maximum amount of kilowatts of electricity. The list of factors that reduce energy consumption should include:
- Saving mode for everyday use - it is reasonable to inculcate the habit of washing your hands with cold water, doing morning toilet activities such as shaving not with the jet on, but using a cup or ladle;
- Wash dishes immediately after eating, when food residues are easily washed off, but if this is not possible, then first soak the dishes in cold water;
- Washing vegetables should be done in a saucepan, having first filled it with water, and do not simply flush the water down the drain;
- For boiling, use a small volume of water needed for one or two servings of tea or coffee; do not fill the kettle to brew one cup;
- For daily water procedures, it is recommended to use a shower, which will take 30-40 liters, rather than a full bath with 140-150.
It is recommended to use an instantaneous water heater for domestic needs (washing dishes, for example) to reduce electricity consumption
But as regards specifically regulating the performance characteristics of boilers and heaters, the following measures are recommended:
- Set the maximum temperature in the tank at 35-40 degrees;
- For a flow-through heater when cooking and washing dishes, heating up to 40 degrees is sufficient;
- To take a shower or fill a bath, a temperature of 45-50 degrees is sufficient;
- Set a daily timer for the storage device with the heating function turned off at night;
It is not difficult to determine how much electricity a boiler consumes per month; it is enough to carry out simple calculations using the following indicators as a basis:
- Electric heater power according to the technical specifications of the instructions - W;
- Maximum tank volume - V;
- The temperature of heated water to a maximum of 60 degrees - T2;
- Temperature of the supplied water for heating from the water supply T1;
The calculation is carried out using the formula: T=0.00116 * V (T2 –T1) / W.
First, the heating time of the full volume of the tank is determined, and then the total energy consumption of the device.
To heat a volume of 50 liters from 15 to 60 degrees with a boiler with a 1.5 kW heating element you will need:
0.00116 * 50 (60 – 15) / 1.5 = 1.74 hours or 104 minutes
To find out the amount of electricity consumed, multiply the power of the device by the heating time:
1.74 x 1.5= 2.61 kW.
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Installation and connection methods
Installation of instantaneous water heater
A instantaneous water heater can be installed independently only if you have special knowledge and skills. Otherwise, it is better to call a specialist. But in general, this is a simple process that consists of the following steps:
Checking the electrical parameters, selecting and purchasing the water heater itself. Pipe mounting. It is better to install the product close to the most consumed points, for example, near the shower or bathtub. At the same time, it should be convenient to turn it on and regulate it. Non-pressure models are usually mounted directly above the sink. If the set, in addition to the mixer, includes a shower head, you also need to think about a place for it. In this case, it is better that the water heater itself is protected from direct contact with water (although they are usually protected from moisture). Wall mounting
It is important to place the loops at the same level to avoid air pockets inside the device, drying out of part of the heating element and overheating. Electrical connection. A prerequisite is the presence of a residual current device (located on the panel) and grounding
All wires are marked with different colors - it is very important not to mix them up, otherwise either the device will not work or a short circuit will occur. The wires are connected to the terminals and fixed in them with mounting screws. Water connection. For piping, holes are provided in the housing - for cold water inlet and hot water outlet. If there is a shower hose, it is connected instead of a hot water pipe.
How to reduce boiler energy consumption
When you find out how many kilowatts your boiler “eats” in a month, you will want to limit its appetites. We can give some advice on this matter.
Record how long it takes for the boiler to completely cool down. If you leave your home for this time or longer, drain the water from it and turn it off.
Touch the top of the boiler. If it is warm, it means it is not insulated enough. You can install additional thermal insulation, at least in the upper part.
Consider installing an additional indirect heating boiler. In the cold season, it will heat the water, for example, from the heating system. And the water entering the electric boiler will have a higher temperature.
If your water heater has a controller or timer, set it to turn off when you are not home. And it turned on an hour or two before your arrival. Determine the switching time yourself, depending on the volume of the tank and its power.
Monitor the condition of the heating element. A dirty heating element with a lot of scale does not heat the water efficiently.
When installing the boiler, place it as close to the water intake points as possible. Insulate the pipes well with special metallized thermal insulation.
