Heating water with a solar collector. Hot water supply in the house (DHW) Rapid water heating

To solve the problem of hot water in an apartment or a private house, in the country, you can heat water using electric water heaters. There are several types and in order to decide which water heater is best for your situation, you need to know their advantages, disadvantages and features of each type of equipment for heating water.

What are domestic water heaters and how do they differ

• flow type - they heat the water passing through the device;
• storage type - the water in the heater tank is heated;
• flow-accumulative - have two modes of operation;
• bulk.

It is difficult to say which water heater is better. If we talk about the appearance, then the main external difference is the size. Storage models are large, flow models are small. But size isn't all it takes to figure out what's best for you. You need to know the advantages and disadvantages of each type of equipment.

Cumulative models

The storage water heater (the second name is the boiler) has a solid size capacity - from 30 to 200 liters. Inside is a heating element - heating element. It may be one or more. The heaters can be switched on in parallel (always work simultaneously) or in cascades (turn on as needed). When cascading, there are several heating modes - for more rational use of electricity.

Many more models contain a thermometer to make it convenient to control the temperature of the water and a thermostat to maintain the set temperature. The desired temperature is set by turning the thermostat knob to a certain position.

A certain volume of water is constantly stored in the storage water heater. It is heated by electric heaters. They are of two types:

• heating element ( T ribbed E electro H heater). Inexpensive classic solution. They are quick and easy to change, in any specialized store is available in a wide range. The disadvantage is that it takes a long time to heat the water.
• Spiral heating element. More powerful heaters that quickly heat large volumes of water allow you to accurately maintain the required temperature. But they are more expensive (affects the price of the water heater), and their replacement is also more difficult.

Principle of operation

Regardless of the type of heater installed, the principle of operation of the storage water heater is the same. When the set temperature is reached, the thermostat cuts off the power supply, heating stops. Further, the temperature is maintained automatically. When the water cools down by 1 degree or cold water is added to the tank at a flow rate, the heating is turned on. As soon as the set temperature is reached (or rather, a degree higher than the set one), the heating stops. This is how automatic storage water heaters work. They are convenient because they do not overheat (if the automation is working) and you always have hot water that is heated the way you wanted. Such equipment usually has two modes of operation - with or without temperature maintenance - in manual mode.

To keep the water temperature as long as possible, use a heater. It is laid between the walls of the tank and the body. With good thermal insulation, even with hot water, the case remains cold, maybe a little warm. It is clear that if the temperature is maintained for a long time, the cost of maintaining it is small. Even if you turn off the keep warm function, the water will be hot even after a day.

There are very simple electric water heaters in which there is no thermostat. They are turned on / off by a toggle switch - manually. As you understand, in this case, there is a possibility that the water heater will boil and fail (if you forget to turn it off).

There is one more nuance - the stepped inclusion of heating elements. They are usually installed in the case two or more, they also make several heating modes. One is more powerful, in which all heaters are turned on, the rest are softer - one or two heating elements can work, depending on their total number. What is it for? In summer, you can use heating in a gentle mode - the water heats up so quickly, in winter they usually use all heaters - there is less waiting. And in general, it is possible to regulate the heating rate of the boiler in this way. They drained all the hot water and need the next batch quickly - they turned it on at full power, there is no such need - you can not overload the networks by turning it on at half power.

What materials are tanks made of and features of their maintenance

Tanks of storage water heaters are made of stainless and ordinary steel. Ordinary steel is covered with protective layers of enamel, stainless steel does not need them. From this point of view, it is easy to say which water heater is better - with a stainless steel tank. But it's also more expensive. But the service life of such equipment is much longer - enamel, even the highest quality, peels off over time.

To prolong the life of the enameled coating, magnesium anodes are installed in storage steel water heaters. They require periodic replacement - they “melt” during operation, and a special sensor with an indicator displayed on the front panel monitors their condition. The status of the indicator monitors the need to replace the anode.

How to choose and which one is better

In most cases, storage water heaters are installed in private houses or in apartments of multi-storey buildings where there is no centralized hot water supply. Equipment is selected according to the volume of the tank. If you do not like restrictions, you can count at the rate of 50 liters of hot water per family member. This should be enough. In the tank, it heats up, say, to 70 °. It is unrealistic to use this, you will dilute it. As a result, there will be 100-150 liters of warm water per person (depending on the temperature of the water in the water supply). This is without taking into account the fact that during consumption, the water is also heated.

Everything is clear about the material of the tanks: there is a possibility, it is better to take a storage electric water heater with a stainless steel tank. The number of operating modes is not so critical, but also a good option, although such models are more expensive due to a more complex circuit.

Which company is better to choose. No one can objectively tell you which water heater is better - people have different needs and requests. But here are some conclusions that can be drawn from the operating experience. People speak well of the storage heaters of firms:

• Termex. If we talk about the prices of water heaters with a stainless steel tank, then this company has no competitors for the price. The quality is hard to say, reviews are different.
• Real. Good storage boilers, the main thing is that there are consumables in your city.
• OSO. Very good but expensive.
• Electrolux (AEG). Well-known company with stable quality.

Instantaneous water heaters

The instantaneous water heater has more modest dimensions. This is a small box that is attached to the wall. Inside there is also a tank with a heating element, but their dimensions are very tiny, and heating elements usually have the form of a spiral - in order to better heat the passing water.

One of the required elements is a flow sensor. It monitors the appearance of water movement in the device (the tap is opened) and gives a command to turn on the heating element. When the tap closes, the flow sensor turns off the power.

There is also a thermostat that sets the temperature of the water. It can be of a rotary type with a scale, there are models with an electronic display with push-button or touch control.

Pressure and non-pressure instantaneous water heaters, their connection

There are two options for instantaneous water heaters - system and individual. The system ones cut into the risers of cold and hot water, they are also called pressure ones. Several points can provide at once - for example, a shower, a sink and a washbasin. There are system instantaneous water heaters for 220 V with a relatively small power consumption (about 8-9 kW), but they can heat a small amount of water. There are very powerful installations - up to 32 kW, but they are three-phase - 380 V.

Pressure borers have two broad classes.

Individual instantaneous water heaters - non-pressure - are connected to cold water. At the outlet they have a flexible hose with a nozzle or, alternatively, a faucet for washing. These devices are good for the period of DHW shutdown or as a solution to the problem of hot water in the country.

Please note that the shut-off valve is only in the supply and you can only turn off hot water with its help. Connecting shut-off valves at the outlet will sooner or later lead to a rupture of the tank in which the water is heated. This happens when the automation does not work to turn off the water. And it is not designed to track water consumption, but only monitors its appearance / disappearance at the inlet. So sooner or later failure occurs.

When connecting pressure and non-pressure versions, grounding is mandatory. And in general, it is desirable to pull the power supply to such partings by a separate line - a large power consumption, a combination of water and electricity is an unsafe combination. Ordinary wiring may not withstand. Therefore, a separate line is needed from, on which the machine and RCD are located.

Type of control

There are two types of flow type water heater control:

• Hydraulic. When there is a flow sensor at the inlet (the first photo in the section), at the signal of which the heating element is turned on / off. The disadvantage of such a system is that it always turns on at the same power. Some models have several power modes, but they must be forced to change each time (press the buttons).
• Electronic. The work is controlled by a microprocessor, which monitors the status of the device using several sensors. These systems allow you to maintain the required temperature.

Hydraulically controlled instantaneous water heaters can only add a certain number of degrees to the water temperature. Which one exactly depends on the power of the heating element, but on average it is about 20-25 ° C. This means that in summer you will get quite warm water at the outlet - about + 40 ° C, and in winter it will only be slightly warmer than + 20 ° C, since the inlet is very cold and it is simply not able to heat the device to higher temperatures.

More powerful models - system ones, with the Sistem prefix - are electronically controlled and can cope with the task of maintaining the set temperature. Their disadvantage is that they require a lot of power and high cost. But if you have such an opportunity, the automation will maintain a constant (set by you) temperature at any time of the year. The installation rarely works at full power, but still it is required to pull the power supply line at maximum power and use it to calculate the machine and RCD.

What are flow heaters made of?

The internal filling can be:

• From copper. These models differ in very good characteristics - they quickly heat the water. Copper has a high thermal conductivity, quickly transfers heat.
• From stainless steel. A good option, durable (if the water is not hard).
• From plastic. The cheapest and not the most durable. Although special plastic is used, it is better not to buy such threaders.

The choice of instantaneous water heater on this basis is obvious. If possible, buy with a copper "stuffing", but stainless ones work well.

They pull power with a copper wire with a cross section of at least 3.5 mm (with power consumption up to 7 kW) and 4 mm - up to 12 kW. According to the value of the current consumed, an automatic machine is selected, the RCD is taken a step higher with a leakage current of 10 mA. With this method of connection and normally working grounding, there will be no problems.

Features of choice

When choosing an instantaneous water heater, you need to focus on several indicators:

All these parameters should be in the description. Having picked up several models, you can then, according to reviews, or based on technical characteristics, decide which water heater is better. If we talk about firms, then German and Italian devices are better in quality. With Chinese - as lucky, although many firms have moved production to China. And now most household appliances have a dual “citizenship” - they usually write - the home of the brand and the place of production. Most of such equipment works reliably, as firms value their name and introduce strict control over product quality.

Specific Models

There are instantaneous water heaters of a non-standard format. The most common is a faucet with instantaneous water heater. This is an interesting option for giving, for example, but it’s hard to say how things are with maintainability - there are not very many users of such devices yet and operating experience is very small.

Which water heater is better: instantaneous or storage

Deciding which water heater to buy - a boiler (accumulative) or a protochnik - in principle, is not difficult. First of all, the limiting factor is the power consumption: for storage it is maximum 3-4 kW, for instantaneous water heaters it is pointless to take less than 7-8 kW - they can only provide heating of a very small amount of water. Not everyone has the opportunity to install such powerful equipment.

Secondly, you need to look at whether you will constantly use an electric water heater or only periodically. With occasional use, especially in summer, instantaneous water heaters are convenient, and moreover, of an open type (individual, which are installed next to the sink). For example, this is a great way to heat water to a comfortable temperature if the sun has not coped with this task. It is also a way to solve the problem in apartments when the hot water supply is turned off for repairs.

For permanent and regular use, storage water heaters are more economical and convenient. Modern models “keep” the temperature for more than a day, so the electricity consumption here will be rather less than more.

Instantaneous storage water heaters

This is a combination of the two devices described earlier. They work in two modes. If the water flow is small, water is supplied from the storage tank, if it increases, flow heating is also connected. The equipment is very convenient, but expensive. There are not so many options. These are Stiebel Eltron SHD 30 liters and 100 liters. Price - $ 1500-1750.

Bulk water heaters

An excellent solution for giving or in case of lack of tap water in the house. A bulk water heater is a container with a lid in which a heating element is mounted. The container can be made of stainless steel, plastic, ordinary enameled steel. The temperature is controlled by a thermostat. A shower hose is attached to the body.

There are two types of such devices - gravity and with a small built-in pressure pump (Alvin EVBO). Self-flowing bulk water heaters must be hung above the head. You can take a shower, then the flow of water will be weak. Models with a pump have more pressure, but the tank capacity must also be decent and you cannot call such a model a marching one.

The functions here might be:

Bulk water heaters are a primordially Russian invention and all manufacturers are Russian. There are similar electric water heaters of the following brands:

• Success;
• Alvin Evbo;
• Aquarius;
• Elbet;
• Mr. Hit Summer Resident;
• Story.

The devices operate from a 220 V network, their power is about 1-2 kW, the price is from $20 to $100, depending on the functionality and material of the tank. Which water heater is better in this category? Stainless with pressure, but these are just the most expensive models.

Summer, summer cottage, swimming pool - the dream of city dwellers. And many, seeking to realize it, get out in the hot season closer to nature. But here's the problem: the main equipment was bought from the street version, and the heating device is not included in its kit. Therefore, we will consider in more detail the methods of how to heat water in the pool. And first, let's look at what design options for swimming exist.

Types of pools

For summer cottages and suburban housing, seasonal models of street performance are very popular:

• Inflatable. Such designs gained their fame due to the low price, ease of installation / dismantling, mobility. Most often they are purchased for children. Small volumes, low boards provide safety for kids.
• Frame. Types and volumes of such models are numerous. They are affordable, easy to install and portable. Bought for a family vacation.
• bowls. This option applies to stationary. Shape and size can vary. Buy for the whole family. Installation is simple, the price is quite high compared to previous options. Requires a supply of communications.
• Concrete. The most expensive of the above and technologically complex option. But the design, volume, dimensions are made for any request. When arranging such structures, a heating system is thought out even at the project stage.

As you can see, the modern market offers a wide range of models.

You can purchase a budget option or start a major construction of a street covered structure.

Temperature standards

There are a number of indicators of a comfortable stay in the pool. One of them is the optimal temperature regime. For an adult, it should be within 24-28 ° C, for a child - 29-32 ° C. Such temperatures are provided for active water recreation without harm to health. Therefore, how to warm up and keep warm in the pool is one of the hot topics of the summer.

Heat saving elements

Before considering the question of how to heat the water in the pool, you should familiarize yourself with the methods of heat saving. There are several options:

• Covering material. As a rule, the structure is covered overnight to prevent strong cooling. The same material will help to warm the water a few degrees if the pool is left covered during the day. Bubble wrap is considered the most effective option.
• Sometimes a pavilion is made over the pool. Some craftsmen use old greenhouses. This option amazingly retains heat at night and allows you to heat water during the day.
• Choose or equip swimming structures with bottom colors that will absorb heat. This will significantly speed up the process of natural heating of water from sunlight.

The considered measures can be applied in a complex way, they will significantly reduce the cost of heating the liquid with the help of electricity.

How to quickly heat water in an inflatable pool

Such structures have a small volume, so one of the popular ways to increase the temperature is to heat water in containers on a separate heat source (gas, electric stove, electric kettle, fire, bath).

After that, it is carried and poured into the pool, achieving the desired temperature. The method is one of the simplest and safest. But it is suitable for small volumes, for example, children's designs.

Some try to heat the water in the pool with a boiler. Yes, it can be done. But do not forget about safety. If this method is used in a place where there are children, then they should not be left unattended even for a second. The consequences can be very sad, given the childish spontaneity and curiosity. Therefore, think several times about the safety of this method before using it.

We have considered two options for how to heat water in an inflatable pool, now we will get acquainted with other, more powerful equipment for such purposes.

Flow heater

It is used for structures no more than 35 cubic meters. m. The principle of operation is based on the circulation of water through a container with a built-in heating element. The recommended inlet fluid temperature must be at least 18°C. The cost of such equipment is low, but there are significant costs for electricity. The power consumption of the installations is from 3.5 to 18 kW. Using a covering material, you can partially reduce these costs.

heat exchanger

"How to heat water in a swimming pool without electricity?" is one of the popular questions. Heat exchangers are just such devices operating from the heating system. They are presented in which there is a coil. This equipment also includes a circulation pump, thermostat, valve. The liquid from the heating system is supplied to the coil, and the water for heating is supplied to the cylinder itself. Having reached the desired temperature, it enters the pool. The operating parameters are set using a thermostat. The power of such installations reaches 200 kW, which is suitable for heating a large volume of water.

The minus of the heat exchanger is depending on the heating of the house. In the summer, it is usually irrelevant. Therefore, a separate working circuit will be required to heat the pool. And this will entail a reworking of the gas heating project and extra financial costs.

Solar collectors

How to heat water in the pool in the country, using natural resources? This issue is especially relevant in areas where there is no connection to gas, and the supply of electricity is unstable. Solar collectors in such cases become an ideal solution to the problem.

Nowadays, such equipment is purchased in stores selling pools. The installations are quite compact, and they can be located near the structure for swimming. When heated, the collectors transfer thermal energy to the water in the storage tank, after which it enters the pool. This method will allow you to quickly reach the desired temperature in sunny weather, but this will not work in cloudy weather. One collector module can heat up to 30 cubic meters of water, respectively, their number is selected according to the required volume.

Such equipment should not be purchased in regions where cloudy weather prevails. It will not be economically justified, because you will have to use additional devices for heating.

solar mats

This type of solar collector is presented in the form of two cuts of a black film, soldered in such a way that channels for water circulation are formed in the internal space. Such a system is connected to a conventional pump, which is included in the set of basic equipment. How to heat the water in the pool with such a device? Quite simply: it is launched to the surface of the water, and the pump is placed on the bottom, from where it will supply liquid for heating.

This design works from a conventional network. Minus - designed for small volumes and depends on sunny weather.

Heat pumps

This is a fairly new, and therefore an expensive way to heat water in the pool. This equipment is interesting in that it can be used in two directions at the same time: as an air conditioner for the home and a water heater.

The principle of operation is based on the technology of conventional air conditioners, only in the opposite direction. Swimming water is heated in the condensate system, and the refrigerant cools down due to this. The heat itself is taken from the surrounding air.

The power consumption of such a device is three times lower than that of an instantaneous water heater. Therefore, the high purchase price will justify lower energy costs. This equipment is also notable for the fact that it can work effectively at an ambient temperature of +5 °C. Having dealt with factory devices, it is worth familiarizing yourself with what folk craft offers in this area.

Rubber manifold

For this type of water heater, they take an ordinary watering hose, preferably black, and lay it in a plane in the form of a snail. One end is attached with clamps to the hole in the pool, the other - to the pump filter. Circulating through the formed system, the water is heated. This method is good for sunny days. This is one of the ways to quickly heat the water in the pool.

wood heating

A coil is taken, the performance depends on the size of its spiral. It is better to prefer stainless steel. One end is connected to the hole in the pool, the other - to the pump. The coil itself should be mounted in a container in which firewood will be burned. This is a fairly effective option for how to heat water in a frame pool.

For greater effect, you can make a coil - a container for burning. That is, firewood will burn in the inner space formed by the tubes. This is an even more efficient device for heating water.

This method is distinguished by low price, independence from energy carriers, high speed, independence from weather conditions. The disadvantages include the need to control heating. Overheating can cause the pool to warp.

A few important points

Since heating water in the pool using electricity and heating is quite a costly exercise, the field for craftsmen to work is quite wide. An interesting direction is the use of natural resources such as wind and sun. By "taming" them, you can get a free and high-quality source of energy, which is suitable not only for but also for other needs.

Be careful with homemade electric heaters. It is necessary to observe all safety measures during their creation and operation, do not disregard this process and keep children away from it.

If we consider factory products for heating, then the choice depends primarily on the financial component. You should pay attention not only to the initial price of the equipment, but also to the costs that will be required during its connection and operation.

Swimming in pools is one of the most popular types of recreation for Russians. Therefore, the topic of water heating is always relevant. Which choice will be made depends on the weather conditions of the region, the parameters of the pool, financial possibilities. The main thing is to observe the installation technology and safety measures during operation.

Every year, traditional energy sources are becoming more expensive, and there is no end in sight to this price race. Meanwhile, the most powerful source of energy, which we see almost every day, "works" for free. And if humanity has not yet learned how to effectively receive energy directly in the form of electricity, then any person can use the thermal energy of the sun - there would be a desire!

Indeed, in a sunny area, the luminary sends approximately 1 kW of energy every hour. It is a sin not to use such a source at least for heating water. At the same time, the cost of creating and installing a water heating device is minimal. Inventors in the vastness of the country have long been using a variety of installations for heating water.

Among them are the simplest and more complex, with automatic control. It all depends on technical readiness, financial capabilities and, of course, desire.

How do craftsmen get hot water from the sun today?

Creating a solar heater with your own hands is not difficult at all.

This is the easiest option.
The usual container in the form of a barrel, an old tank, is installed on the roof of a summer shower or a house, a barn and connected through a hose to an ordinary tap.

If the container turns black, heating will occur faster.

By the end of the day, the water warms up to about 45C. These data are valid for a polyethylene tank of 200-300 liters. It is desirable that it be flat - this increases the heating efficiency.

The whole disadvantage is that all the water must be used in the evening, because. it will be cold in the morning.

To “eliminate” this drawback, you will have to insulate the tank itself or drain the heated water into an insulated tank again. You can simply feed the water into the boiler and, when it cools down, heat it up. At least some electricity, but it is saved.

Another option is to keep the boiler permanently connected to a roof-mounted tank. Then the water will constantly circulate; it can be used online.

A significant drawback of the system is that it does not work at temperatures below +20C. Therefore, there are other ways to heat water in the off-season.

Solar water heater - collector

Such a device is considered the most effective. It's all about the material from which the collector is made. Most often it is:

• steel
• brass.

But assembly using metal is laborious (soldering, welding, sealing, etc.), so other materials are used. There is an option to use polypropylene pipes - they are cheaper. However, their connection can also cause difficulties associated with sealing joints.

Another disadvantage is a significant deformation during heating, this is not so noticeable for metal-plastic pipes, but polypropylene has a high coefficient of thermal expansion. This deficiency can cause leaks in the system.

There is an original and simple solution, which is to use a garden hose as a solar collector. The whole assembly process is limited to twisting it into a spiral and placing it in a suitable box.

Excellent flexibility, no connections guarantee no leakage, and the length of the hose allows it to be connected directly to plumbing fixtures without intermediate connections.

The performance of such a system depends on the length of the hose. With a diameter of 2.5 cm and an air temperature of at least +25C, one meter of the hose heats 3.5 liters of water up to +45C.

It turns out that on a sunny day by the evening 10 meters will "give" you 280 liters of hot water. The system works when the temperature drops to +8C.

How is the process of heating water

The sun's rays fall on the spiral through the glass and heat the spiral. The heated water becomes a source of long-wave radiation, which is reflected from the glass. That is, the sun's rays are in a kind of thermal "trap".

1. To create this heating device, you will need a box where a black hose coil will be placed, using other shades will result in a loss of 5% of heat. It can be rubber or PVC. Diameter - not less than 1.9 cm, wall thickness not more than 2.5 mm.
2. The hose will connect to the boiler, which should be above the spiral. The bottom of the box must be insulated with foam, painted black.
3. The box itself is closed on top with window glass (organic glass is not suitable due to the fact that it does not retain solar radiation well).
4. A rubber gasket must be installed between the glass and the box.

Water heater from PET bottles

The idea is to first create modules (3 bottles each, you can also 4, 5), then connect each of them to a plastic pipe, which is connected on one side to a source of cold water, on the other hand, it gives out hot liquid. It is best to use bottles with a capacity of 2-2.5 liters. It is necessary to connect them according to the principle "neck to the bottom".

• To do this, a hole is cut in the bottom for the neck with a diameter of 26 mm. The hole must be located strictly in the center. Therefore, first mark the center by drilling a hole with a 3-6 mm drill.
• To ensure sealing, lubricate the threads on the neck with sealant and leave the structure stationary for 2-3 days. Poke a hole in the bottom of the top bottle!
• A module of three bottles in the same way (you can think of some other) is attached to a plastic pipe, at one end of which cold water enters.

The number of modules can be large. To get 200 liters of hot water, you need about 110 bottles - this is three square meters of area.

• Place the resulting block in a box covered with window glass. The angle of inclination is from 10 to 30 degrees.

The resulting system is much more efficient than a black water barrel mounted on the roof.

Most home-made designs for heating water by the sun in summer save 70-80% of the energy spent on heating. In autumn, spring - up to 40%. At the same time, up to 400 kW / h per person is “taken” from the luminary in a year! There is something to think about.

In this article we will touch on the problem of heating water. It happens that there is a task to heat water. This task most often occurs in hotels, recreation centers, i.e. where you need to provide a large number of people with hot water.

How can water be heated?

There are many ways to prepare hot water:
With heat pump
With a gas boiler
With a diesel boiler
With a solid fuel boiler
Using an electric boiler or heating elements
With solar collector or panels

And so on, we will not list everything, otherwise the article will turn out to be too long. We have listed the main methods. Everything seems simple: you have network gas, and you need to heat several indirect heating boilers. To do this, it is enough to connect the gas boiler and boilers with a pipeline. They called a plumber, bought pipes and fittings, the plumber put everything together - and voila! ... the boilers do not even have time to heat up to 50 ° C.

What is the reason?

The thing is that your boiler is simply not suitable for heating such an amount of water in terms of power. And most likely, you simply did not calculate the power sufficient to heat the water.

How to calculate the required power for heating water?

This is not a very difficult task, and you can calculate the power needed to heat water yourself. Arm yourself with a calculator, and paper, a pen. To heat one liter of water, one degree Celsius requires a thermal power of 1.16 watts.

For example, you have a 500 liter water tank and you need to heat water in it from 20°C to 80°C. We believe that 80°С - 20°С = 60°С is our delta. 500 l. * 60°C * 1.16 W = 34,800 Wh or 34.8 kWh. This is the required power to heat 500 liters from 20°C to 80°C in one hour.

And if you have a gas boiler installed, with a capacity of 25 kW / h, then naturally it will not be able to heat 500 liters. water up to 80°C in one hour. Therefore, with insufficient initial power, these powers are compensated only by the heating time. What entails an increase in the boiler volume. In addition, you need to understand that heat losses still occur in the system. Therefore, these figures are approximate.

It is worth noting that the consumption of hot water is directly related to the number of people who use it. According to SNiP for hotels, with a shower in each room, the water consumption per person will be 140 liters per day. According to our data, the actual consumption of hot water in hotels is 50 liters per day, per person.

Heating water with a solar collector.

Let's calculate how to heat water with the sun. Imagine that there is a hotel in which the water needs to be heated by solar energy. This hotel has 40 triple rooms and 20 double rooms. We want to organize the heating of hot water with solar energy.

We consider the maximum occupancy of the hotel: (40 * 3) + (20 * 2) = 160 people will live in this hotel. They need 160 people. * 50 liters = 8,000 liters of hot water per day. In hotels, as a rule, there are two peaks of water intake, this is in the morning (from 8.00 to 10.00) and in the evening (from 17.00 to 20.00). This means that we need to provide at least 3,000 liters of hot water for morning water intake, and at least 5,000 liters of water for evening water intake, since evening water intake is usually larger.

It should be noted that by the term "hot water" we mean water with a temperature of 60°C. In order not to install storage boilers with a volume of 5,000 liters, you can heat the water up to 80 ° C. This will reduce the capacitive volume to 3,500 litres.
We consider the required power: 6,500 liters * 60 ° C * 1.16 W, we get 452.4 kW / h, we need to spend to heat this amount of water.

How many solar collectors do you need?

Now we consider how many solar collectors we need. The roof of our hotel faces south, so we believe that solar vacuum collectors will operate at full capacity.
Power of one vacuum tube with 24mm. capacitor is conditionally equal to 65 W / h. Solar collectors will work 10 hours a day, from 9.00 to 19.00 (ideal). Under such conditions, one tube will produce 650 W / h in one day. We divide 452.4 kWh by 0.65 kWh (650 Wh) and we get 696 tubes. These are 23 solar collectors of 30 tubes, or 35 collectors of 20 tubes.

And how many collectors with 14 mm are needed. capacitor? One tube of such a collector produces about 50 W / h at the peak, or 500 W / h in ten hours. We divide 452.4 kWh by 0.5 kWh (500 Wh) and we get 905 tubes. These are 30 solar collectors of 30 tubes or 45 solar collectors of 20 tubes.

We carried out all these calculations in ideal conditions, with excellent sunny weather, did not take into account the water consumption during heating, if you need more accurate calculations, please contact us. We will calculate, supply the equipment and mount you an excellent and, most importantly, working solar system.

There are two main ways to prepare hot water. First, the water is heated while moving through the heater and is supplied to the water intake. Such a heater is called a flow heater.

The second way - a large volume of water is heated in a heat-insulated container, then it is gradually consumed. Such a heater is called storage. The energy source is usually gas, electricity or heated coolant from the heating system.

Flowing - high peak power

The flow heater must be relatively powerful in order to provide the required flow of hot water in the faucet. For a shower head, a power of at least 10 kW is required, for filling a bathroom - from 15 kW, for two hot water taps - from 20 kW.

Heating water with an electric instantaneous heater is not cheap. In addition, you need a three-phase connection (over 6 kW) and a special permit for high power.

Optimally, to provide several taps, install a compact electric flow heater on each of them. At the same time, protection is put against their simultaneous operation so as not to overload the network.

A cheaper option is to heat water with gas. A geyser, or a second circuit of a heating boiler, is used. The power of such devices can be enough for two taps, and hot water is cheaper.

Disadvantages of flow

With a flow circuit, the heater should be located as close as possible to the faucet in order to drain less water until it is hot. The recommended distance is no more than 5 meters. But in any case, there will be an overrun of water and energy. A similar drawback is typical for the storage heater.

Another drawback of the DHW (hot water supply) flow circuit is the inability to take some hot water. Each device has its own minimum power. Therefore, at low water consumption, it simply does not turn on.
As a result, water and energy are also wasted.

Pressure surges in the system bring discomfort, as they change the outlet water temperature.

In retail outlets, in order to sell an unsuitable flow-through electric heater, they simply indicate that it gives out so many liters of water at such a temperature, for example, +50 degrees, which is acceptable at first glance. But it does not indicate at what temperature the water is heated. The key characteristic of such an apparatus is the difference in temperature heating. After all, cold water is usually +6 - +10 degrees, and not +15 or +20.

Accumulative water heating system

The main advantage of an electric storage tank with a power of 1.5-2.0 kW is that it can be installed everywhere, in any house and apartment where there is a 220 V power supply. Its volume is usually 25 - 150 liters (running volume 50 - 100 liters) . The water in it is heated gradually to a predetermined temperature, and during the intake a large flow rate is possible, the temperature decreases gradually.

It is cheaper to heat water with a gas storage heater with a low-power burner (up to 3 kW). The fact is that such a heater does not need a special chimney. But it can be installed only in agreement with Gorgaz, probably on a separate project. It is provided with air from the room (with an exhaust system).

Disadvantages of cumulative

• Limited water volume, which can create difficulties. For example, if one serving in the volume of the tank is used for bathing, then it takes a long time to prepare the next volume.
• The heater must be installed next to the water intake, if the bathroom and kitchen are separated, then a separate storage tank must be installed for each tap.
• There is an overexpenditure of energy from the cooling of unused hot water in the heater.
• Excessive consumption of water when draining water from a tap that has cooled in the pipeline.

Indirect heating boiler - stable DHW system

The advantage of an indirect heating boiler is that the energy from the heating system is used for heating, which is plentiful and usually not expensive. Therefore, there can be a lot of hot water, its temperature is stable, and water is cheaper.

The indirect heating boiler is a storage capacity of 100 - 300 liters. Heating is carried out by a spiral pipeline, through which a coolant heated to 80 - 90 degrees moves.

Heating systems are created in such a way that when the hot water supply cools below a threshold value, for example +50 degrees, the boiler switches to heating the boiler. At the same time, it gives out an increased temperature; it works at full capacity, heating the DHW to the upper threshold value, for example, +60 degrees. Then it switches back to heating.

With buffer capacity - the highest energy reserve

In the buffer tank, the opposite is true - a large volume tank is used, about 1 ton or more is filled with a coolant, and the heated water moves in a spiral, i.e. direct heating takes place. But when additional taps are opened, its temperature changes slightly, since the design has a large reserve in terms of the amount of transmitted energy.

The temperature of hot water will be the same as that of the heat carrier of the heating system. Sometimes this is not suitable, so a mixing unit is also included in the water supply circuit to reduce the temperature ...

The buffer tank is mainly supplied with heating systems with solid fuel boilers.

Other features of water heating by heating

The boiler is often supplied with single-circuit gas or liquid boilers.

Another feature of the system is the possibility of creating a constant circulation of water through the annular water supply pipeline. Then, when you open the tap, you immediately get hot water. The cooling of water is not considered a loss of energy, because it is spent on heating the house.

There is still an opportunity to save money - an additional heating coil is placed in the boiler and connected to the solar collector. Solar energy is called free, the cost of solar collectors in this case pays off. This makes it possible to heat water in the summer, if there is not enough energy, the boiler is connected.

Layer heating boiler

The main disadvantages of a conventional once-through heating system with a gas heater (secondary boiler circuit) or an electric heater are solved by installing a layered heating boiler. One or more per faucet. It is a heat-insulated container into which hot water is supplied from above. From the same level, its fence is carried out.

Such a boiler makes it possible to simultaneously receive a lot of hot water of a stable temperature. With it, you can pick up "a little water", as well as ensure the smallest descent of the cold. A conventional heating boiler can also be used as such an intermediate storage.

Error - incorrect connection of the DHW boiler

One of the common mistakes when creating a hot water supply system in a house is connecting an indirect heating boiler to the second circuit of a double-circuit boiler. This circuit itself is designed to prepare hot water, therefore it has a maximum temperature limit of +60 degrees, so that thermal burns do not occur.

Now the most comfortable and economical solution for creating a hot water supply system is to install an indirect heating boiler, where it is possible to do so. The remaining DHW schemes can be considered forced decisions that are dictated by circumstances, for example, savings in creating ...