Differences between a single-circuit gas boiler and a double-circuit

Autonomous gas heating gives the consumer a certain independence, allowing him to regulate his own energy consumption. Some units are only capable of heating the room, others can also be a source of hot water. To understand the types of equipment, you need to know the differences between single-circuit and double-circuit boilers. Heating system manufacturers offer a wide variety of power and functionality.

What is the difference between a double-circuit boiler and a single-circuit one

Gas heating equipment can be classified according to the following criteria:

• number of heating circuits provided;
• thermal power that the unit can give out;
• equipment level;
• purpose - household or industrial appliances.

All these plants have one thing in common - they work by burning natural gas.

Hot water supply and heating

Systems in which only one heat exchanger is provided, designed for connecting radiator lines, is usually called single-circuit. Products of this type have a mechanically simple and reliable design.

In addition to heating, double-circuit units are designed to perform another task - to provide the house with hot water. If there is only one heat exchanger inside, the redistribution of the coolant flow between the circuits is carried out due to the operation of the three-way valve. The priority here is the heating of the liquid, which is used for domestic needs. Systems with two heat exchangers make it possible to connect a separate circuit to each of them.

Overall parameters and power of the installation

The more powerful the device is, the larger its linear dimensions will be. The heat output of single-circuit units is selected based on the area of ​​the building, which is equipped with this type of heating. Double-circuit heaters have a peculiarity of poor heat transfer when hot water is drawn from two points. Therefore, in order to avoid the appearance of cold water in the hot tap at the moment of opening the second one, it is necessary:

• install a boiler with a capacity of over 16 kilowatts, if the house has a shower room;
• use units with a heat output of at least 18 kilowatts for apartments with bathrooms;
• use boilers with a capacity of at least 28 kilowatts for rooms where two or more hot water extraction taps are installed.

An area of ​​space of 130-160 squares suggests that a double-circuit or single-circuit gas boiler can often turn on, risking rapid failure of the heat exchangers.

Equipment

The complete set of a double-circuit gas heater assumes the presence of:

• overpressure protection valves;
• a three-way valve;
• circulation pump;
• expansion tank of membrane type.

Some manufacturers equip boilers with additional heating and hot water filters.

Devices of a single-circuit type, as a rule, are not equipped with associated equipment.

How to choose a boiler

Choosing the device for the needs of the room, it is necessary to take into account, first of all, the power of the unit so that it is not less than the heat loss existing in the house. The second task comes down to determining the number of contours. The third - to the choice of the type of design of the device in the matter of the chimney. Other important points:

• The material from which the heat exchanger is made: stainless steel, cast iron or copper coil.
• The design of the product is a hinged device or a floor-standing version.
• Availability of modern automation and electronics.
• The efficiency of the device - the energy efficiency of heating directly depends on it.

Gas heating equipment must meet safety requirements during operation.

Positive and negative sides

For the most part, single-circuit gas heating units have the following advantages:

• They have a more democratic cost than counterparts of the double-circuit type.
• Heat exchangers are simple in design, easy to maintain, reliable and durable.
• They can work in conjunction with an indirect heating boiler.

Weaknesses of installations:

• A sufficiently spacious room is required for the installation of the device and related equipment.
• System maintenance costs can be substantial.

Advantages of double-circuit gas installations:

• At the same time, they solve the problems of heating and providing households with hot water.
• Compact and complete with almost all the necessary additional equipment.
• Ultimately, the overall system on such a heater is much cheaper than with a single-circuit unit.

The disadvantages include:

• There is a time delay in heating the liquid.
• When opening several hot water taps, a drop in temperature may occur.

In some cases, it is impossible to put an additional circulation pump in the line in a flow-through type model.

The nuances of installing heating systems

For gas-powered equipment, a project for its installation is necessarily made. If there is a certain freedom in choosing the place of fixing the boiler, you can indicate some points that will help more correct operation of the device.

It is advisable to mount flow heaters closer to the place where the water intake will be.

If there are two coolant return taps, the distance from the heater should be minimal to the valve from which water is more often taken.

Top manufacturers of double-circuit and single-circuit systems

The most demanded and popular boilers on the market are Italian, Korean, German and Russian devices.

• Bosh is a line of German devices with heat exchangers made of copper pipes with a sputtered anti-corrosion coating. Equipped with advanced electronics and security systems. The service life reaches two decades.
• Viessmann - German boilers with efficiency reaching 93%.
• Beretta - gas heaters of the Italian manufacturer for high power. The devices proved to be excellent in work under severe winter conditions.
• Baxi - heating systems with a quiet atmospheric burner. There are products for any capacity.
• Olympia is a Korean-made double-circuit gas boiler with an automatic weather adjustment system.
• JSC "Borinskoye" ISHMA BSK - boilers from a reliable series of domestic manufacturers with a built-in pump for circulating liquid.

When choosing boiler equipment, you should take a closer look at domestic products and devices of German production. The main arguments are the simplicity of the equipment in service, the reliability of the structural elements and durability.