Pros and cons
Based on the experience of operating different types of boilers for individual heat supply, experts rightly believe that the most convenient to manage is an electric boiler with a circulation pump.
Advantages of tying electric boilers with a pump:
- Full integration of the pump operation with the elements of the thermal scheme.
- Low specific indicators for own energy consumption for the implementation of the tasks set, they practically do not affect the overall heating costs.
- The highest efficiency among other heating sources up to 99%.
- 100% automation of technological processes.
- Environmental friendliness - no harmful emissions into the atmosphere.
- Low specific coefficients of material consumption, there is no need to install expensive equipment on the chimney, create draft in the boiler and organize air supply to the combustion chamber.
In fairness, it should be noted that the system has one very significant drawback - the high cost of electricity for heat generation technology. There are several options for reducing energy costs:
- Effective thermal insulation of the heating object.
- The use of combined heat generation with the inclusion in the scheme of secondary energy sources: solar, wind, water heat pumps.
- Transition to multi-tariff electricity metering with the inclusion in the heat supply scheme of a storage tank for heating water during the period of the preferential tariff.
Installation nuances
Installation begins with the choice of a place for an electric boiler room; when installing powerful units of more than 6 kW, a separate room is recommended without access by unauthorized persons and children. Heating elements of an industrial heating boiler can be installed in the kitchen.
The EC is positioned so that there is free space around it for maintenance and repair.
Minimum gaps:
- to the upper ceiling of the room - 0.80 m;
- up to the “0” mark in the case of a hinged type - at least 0.50 m;
- to the walls - 0.05 m;
- to pipes - more than 0.50 m;
- in front of the boiler front - more than 0.70 m.
The level of the hull location is important - it must be strictly horizontal. The installation of the boiler depends on the type of heating system - with natural circulation, the electric boiler is located at the lowest point, with forced circulation - in any convenient place .. It is possible to install more than one unit, but several, in this case they are tied in parallel so that they work with the same load
It is possible to install more than one unit, but several, in which case they are tied in parallel so that they work with the same load.
Installation algorithm:
- For a wall-mounted structure, first install the brackets that come with the unit.
- After attaching them to the wall with dowels or anchors, the body is hung.
- The floor unit is installed on a flat dielectric stand.
- They tie the heating and hot water circuits.
- Install shut-off and control valves on the inlet and outlet pipes.
- Install the sump sensors, pressure gauges and thermometers according to the working scheme.
- Connect the unit to the mains. Corrugated flexible conduit can be used as a cable channel.
- If power surges in the network are not uncommon, then the connection must be made through a stabilizer.
- Electrical protection is installed, the fuse power is selected higher than the largest current load of the boiler in working condition, grounding is mandatory when connected. Perform grounding of 3- or 5-core in the cable.
- The zero working wire N is connected to the neutral bus of the shield.
- The grounding PE wire is connected to its "Earth" bus.
- For a power line, a brand of VVG cable is used with a number of cores of 3 or 5, with sections of the corresponding EC power, usually the size is indicated in the product passport.
- The double-circuit boiler is tied through a three-way valve of the electric type. At the signal of the thermostat, it directs the coolant flow to heat the DHW or heating circuit.
- After the installation work is completed, the boiler is inspected and made sure that it is installed strictly horizontally and all communications are connected to it.
- The boiler is filled with water and a pressure test is made under tap water - leaks in the connections and the serviceability of the shut-off and control valves are determined.
- Check the operation of the electrical equipment of the boiler and the circulation pump built into the boiler.
- Test the performance of sensors and security automation.
Electric boilers with a pump are the most advanced heating method with the possibility of modern heating control from 0 to 100%. Using the Smart Home system, control can be performed online, outside the walls of the house. And although the pump itself consumes additional electricity for its operation, these costs pay off quickly, taking into account the comfort, autonomy and safety of services.
The most important thing is that this scheme has a great future, given that any secondary energy resources of green energy are easily integrated into it, and therefore this type of heat supply is gaining popularity all over the world.
Criterias of choice
The choice of equipment depends on several factors, but the base is the thermal power of the object. An accurate calculation can only be performed by a specialized organization. But for an approximate calculation, a simple ratio of power and heating area is used for central regions, for example, in Moscow: for 10 m2 - the required power is 1 kW.
The next criterion is the connection scheme, which depends on the possibility of subscriber input of the power grid into the house, voltage and number of phases. For a small boiler of 6 kW (object up to 60 m2), you can connect to a single-phase 220V network, and ECs of higher power will require three-phase networks (380 V). Many manufacturers produce units with the ability to connect to both three-phase and single-phase networks.
When choosing an electric boiler with a pump, you need to take into account the heat output
The next factor is the security system, it must cope with such threats as low or high pressure of network water, overheating of the heating element or freezing of water. EC control is selected from three options: manual, digital or programmable. It is advisable to choose a unit with power control. In budget models, it is stepped, and in devices with programmers it is smooth.
In this case, based on data from pressure and temperature sensors, the software allows you to automatically set the mode. When using a multi-tariff meter, the maximum load on the boiler will be valid from 23:00 to 07:00
Equally important is the presence of auxiliary devices complete with a pump and an expansion tank: temperature and pressure sensors, fittings and pressure gauges
Equipment power calculation
After the calculation of the thermal scheme is performed, the number of circuits, the length of the network are established, and the point for the source location is selected, they proceed to the selection of EC parameters.
In the distribution network, they are sold with a power of 2 to 70 kW, and devices with a thermal performance of more than 50 kW are used for industrial facilities.
The power calculation is entrusted to a special organization, they use online calculators or calculate according to the formula: Wk \u003d (SxWud) / 10,
where:
Wк - thermal power of the unit, kW;
S is the total heated area, m2;
Wsp - specific power per 1 m2 of area, depends on the climatic region, set: for the southern regions 1.0, for the central - 1.1 - 1.15, for the northern - 1.2.
Calculation example:
The climatic region is the center of Russia.
Heating area - 160 m2.
Thermal power: (160∙1.1)/10=17.6≈18 kW.
This calculation is quite suitable for a single-circuit heat supply scheme, that is, only for heating. In double-circuit schemes with hot water supply, it will be necessary to carry out an additional calculation for the needs of hot water supply, taking into account the SNIP standards for hot water consumption and the number of service users.
The next calculation that will be required in electric heating is the calculation of the electrical network for connecting the unit. An incorrectly selected cable will overheat during operation, creating an emergency fire hazard. For a rough calculation, you can take a simple ratio - a current of 1 A will require a cross section of 1 mm2.
Calculation example for determining the cross-sectional area of the electric boiler cable:
Power - 6 kW;
The network is single-phase 220V.
The calculation formula for the cross-sectional area of \u200b\u200bthe conductor mm2: S \u003d Wk / (U ∙ I).
U - 220 V,
I - 8 A.
Calculation: S= 6000/(8∙220)=3.41 mm2
This is a fairly approximate calculation, you will also need to take into account the material of the cable and its length.
All work on the installation of electrical equipment must be carried out in full compliance with the requirements of industry codes and standards, as well as safety rules:
- Do not install the unit in close proximity to a water supply or water source.
- During installation, observe the recommended building distances between the unit and structures.
- Mandatory connection of the EC to the ground loop is required.
- Installation of the wall-mounted device is carried out on a wall made of non-combustible materials.
- It is forbidden to lay power cables under heating or water pipes. In places of possible intersection of engineering networks, a protective metal casing is installed.
An electric boiler with a pump must be installed in full compliance with all safety rules.
