It is difficult to imagine a comfortable house or apartment without warm water. The proper organization of hot water supply (DHW) is necessary not only for domestic needs, but also is the basis of individual hygiene. Warm morning showers or relaxing evening baths have become routine everyday routines. But few people know the specifics of the organization of hot water supply. What is it, what important requirements must be observed when designing a system and how to monitor its condition? To answer these questions, you need to understand the fundamental principles of hot water supply.
What is dhw: tasks and functions
The main function of this system is to provide water with the proper temperature indicator for a residential or industrial building. In this case, it is necessary to take into account the quality of the liquid, the characteristics of its pressure in the pipes and the method of raising the temperature to the required value. Depending on the last parameter, the DHW system is divided into 2 types:
- Central. Water is heated at thermal substations (CSCs) and already from them using pipelines is supplied to consumers.
- Standalone. To achieve the required temperature regime, special heating devices are installed - boilers, storage boilers or geysers. This type of DHW organization is intended for a small area of a room - an apartment or a house.
Each of them has its advantages and disadvantages. The central system is more convenient for consumers, but only if its operation is constant and meets the standards of temperature and water composition. Alas, such a situation in our country is more likely an exception than a rule. Central hot water supply - what is it, a reliable way to provide comfort in an apartment or a “headache” for consumers? In many respects, this depends on the degree of executiveness of local regulatory and control bodies.
The stand-alone method is more costly, since it requires the installation of special equipment, laying water pipes. However, its operational characteristics and degree of comfort far exceed the central hot water supply. The consumer himself can set the temperature level, control the energy consumption.
Hot water requirements
Frequent scheduled shutdowns and low temperature conditions are the main disadvantages of central hot water supply. Such situations occur frequently, but according to current laws their frequency is strictly regulated. Decree of the Government of the Russian Federation No. 354 defines the following standards:
- The water temperature should not be lower than +40 ° , and its deviation does not exceed 3-5 ° .
- Total dhw shutdown time. What are these and what indicators should be observed? Total time - no more than 8 hours per month.
- The maximum period for preventive maintenance in the summer season is 14 days.
The composition of the water must comply with sanitary standards SanPiN 2.1.4.2496-09.
To control the flow rate of the coolant, special devices for hot water supply are installed. Counters are mounted only by representatives of the managing organization with which an agreement is concluded for the supply of hot water to an apartment or house.
Autonomous systems
The practical implementation of these systems requires a professional approach to each stage of work. For design, you should know the main types of autonomous hot water. What it is and how efficiently a certain type will work depends on the initial technical parameters.
Cumulative
In the boiler of the storage device, water is taken from an external source and its subsequent heating to the desired temperature. A DHW scheme of this type is applicable for country houses and cottages.
Modern boiler designs have a number of additional functions:
- Several operating modes - economical, optimal and maximum. It is also possible to delay the start of heating.
- Thermal insulation of the case provides heat preservation, which directly affects energy consumption.
- A large selection of models that differ depending on the usable volume, functional and operational characteristics.
To achieve the desired level of temperature using electric heating elements - heating elements.
Flowing
In apartment buildings, the use of heat-exchange water heaters is popular. Depending on the installed equipment, the following types of devices exist:
- flow heaters;
- double-circuit heating boilers.
As energy carriers can be used electrical energy or thermal energy resulting from the combustion of gas. The latter method is preferable, since it is less costly and more efficient because of its low inertia.
Regardless of the choice, any DHW system must comply with the standards, fulfill its direct functions and be absolutely safe for users.