Vacuum heating radiators: overview of types, selection rules + installation technology

New developments aimed at saving home heating costs are increasingly attracting attention.New products also include vacuum heating radiators. These are ordinary batteries in appearance, but completely different in operating principle.

They are suitable for both centralized heating systems and autonomous ones. In this material we will talk in detail about the operating principles of vacuum radiators, their varieties, and also dwell on the nuances that you need to keep in mind when choosing heating radiators for your home.

What is a vacuum battery?

The radiator was called a vacuum radiator because the air was completely pumped out of the internal cavity of this steel sectional structure. This was done in order to reduce blood pressure.

A liquid substance is placed in hermetically sealed sections, which tends to evaporate easily at low temperatures. This is usually either ethanol or lithium bromide liquid.

In fact, the operation of a vacuum battery is based on the principle of operation of a sealed two-phase thermosyphon. At the same time, it has good heat transfer properties.

A system with such devices is low-inertia. It quickly reaches operating mode and reacts almost instantly to changes in heat loss.

The table shows the heating efficiency of different radiators.From the surface of the vacuum heating unit, heat transfer into the room begins much faster.

The vacuum battery has an optimal ratio between thermal radiation and convection in the total heat transfer. The first indicator is 80%, the second - 20%.

Types of vacuum radiators

The line of vacuum devices includes products designed for electric heating, vacuum registers, and panel radiators. You can also find exclusive designer products on sale.

The vacuum electric radiator model deserves special attention, although they are more expensive. This is a good solution for owners of rarely visited suburban real estate.

Designer vacuum radiator in the form of a firewood stand. You can not only stack logs on it, but also dry them

Instead of a horizontal channel with a coolant, this device has a cartridge-type tubular heating element with a power of more than 50 W per section.

This heater transfers heat to the filler - oil or water, thereby heating the lithium bromide liquid. When installing such models, grounding is required.

Device and principle of operation

The difference between vacuum radiators and bimetallic And aluminum analogues can also be seen during their external examination. The former have a larger distance between sections. This heating device consists of a body, a horizontal channel and vertical sections.

Simplified diagram of a vacuum radiator. Its main elements are the collector (1) and vertical sections (2) in which the secondary coolant is located

The first of these elements includes two sections made of 1.5 mm steel.The horizontal channel is the primary circuit, located at the bottom and connected to the heat source. A coolant passes through it, transferring heat to the liquid located in sections that are located perpendicular to this channel.

The vertical sections are filled with a secondary coolant - a heat transformer. They are completely isolated from the primary circuit. Their number is directly proportional to the degree of heating of the room. The rate of heating of the liquid affects the pressure inside the cavities. The higher it is, the lower the pressure.

The secondary coolant is a liquid based on bromine and lithium. In the circuit it is in a small volume and tends to boil and quickly evaporate at a low temperature, about 35 °C.

The circuits are well insulated relative to each other and the environment.

The process that occurs in vacuum batteries looks like this:

1. Antifreeze or water heats the horizontal channel.
2. Heat from the horizontal channel is sent to the vertical sections.
3. The heat transformer boils, causing the entire secondary circuit to be filled with steam.
4. The walls of the secondary circuit heat up and release heat into the room.

To ensure effective transfer of heat rays from the lithium bromide liquid to the walls of the radiator, the state of the working substance must be brought as close as possible to the fog stage. Then the heat will be transported by drops of warm liquid.

To achieve this, the basic condition must be met - the pipe inlets must have a temperature of at least 40 and maximum 60 °C.

Vacuum devices provide room temperatures 2-3 degrees lower than traditional batteries. But home heating costs are reduced by an average of 17%

In the case of an autonomous system, it is difficult to achieve such indicators. In areas of the heating system remote from the source, the coolant will cool very quickly. Yield in application pyrolysis boilers with optimal temperature conditions from 45 to 60 °C or from 50 to 70 °C.

The problem is solved differently by installing one mixing unit in front of a group of vacuum radiators. In this case, the low-temperature level will ensure the connection of heated water with cooled water from the return. The operating cycle in the vacuum radiator is repeated after the condensate is lowered down the internal walls.

Positive and negative qualities of devices

The following arguments are usually given in favor of using radiators that do not contain gases in the cavity:

• guaranteed absence of such a phenomenon as airing of the system;
• low hydraulic resistance;
• complete absence or minimal corrosion;
• stable heat transfer, because Dirt does not settle on the inner surface of the case;
• a minimum number of threaded connections, which makes leaks unlikely;
• wide choice of coolant: antifreeze, water, steam, etc.

If we compare these products and the usual water ones, then in apartments heated centrally, the air will not be heated equally. In the second case, the water entering the system heats the entire body of the radiator directly. In a vacuum, water from the central line heats only the lower part.

The use of vacuum radiators saves coolant up to 80%. In addition, when the battery is disconnected, the heated gas particles slow down, so it takes a long time to cool down

The remaining sections of the battery receive heat from the evaporated liquid.Due to the fact that the heat transformer has both a temperature and thermal conductivity lower than that of water, the walls of the vertical sections of the radiator will heat up less.

To ensure the same temperature conditions as with water batteries, the vacuum radiator must have a larger area.

Manufacturers claim that sections of the product warm up instantly. With a small volume of water of 0.5 liters, one fragment has a heat transfer of 300 W. It should be noted here that each section of the now classic cast iron radiator contains 4 liters of liquid.

The savings are especially noticeable when using antifreeze. The costs of its acquisition will decrease significantly. A small amount of coolant and no need for expensive equipment are the main advantages of using vacuum radiators.

The advantage of these devices is the fact that the room warms up more smoothly vertically. According to measurements, for every meter of height the difference is about 0.5 °C. In a room with a ceiling height of 2.5 m between the appliance and the floor this will be approximately 1.25 °C.

The effectiveness of vacuum radiators is manifested when using alternative energy sources, such as a heat pump, solar panels.

While cast iron batteries can heat the room when the coolant reaches a temperature of at least 65 °C, for vacuum devices 35 °C is sufficient

You should know that if a section depressurizes due to some circumstances, the vacuum radiator will not work. The reason is that the pressure inside and outside the housing will be equal.

Such a breakdown poses a threat to the well-being and health of the people living in the house, since the liquid inside is poisonous.

When is a vacuum radiator beneficial?

Based on the features of the vacuum radiator, we can conclude that its use in a centralized heating system will not bring much benefit.

The use of the device is justified when choosing an autonomous heating system. If it is not water that circulates in it, but a non-freezing liquid, then the cost of the coolant will decrease significantly.

A heating system with vacuum radiators is very effective in tandem with a solar collector. For a cottage this is the best modern technology

Installing vacuum batteries is a rational solution to the problem if a low-power boiler is purchased. Such a source will not be able to heat the coolant to the high temperature required for the operation of traditional appliances. In the case of a vacuum unit, this is not required. The reaction inside it will start at 35 °C.

Country cottages, which the owners do not use for permanent residence, take a long time to warm up in cold weather. A vacuum radiator will speed up the process. The heating process with its participation occurs quickly, and the heat is distributed evenly.

Product selection rules

With the growing popularity of this high-tech equipment, there are more and more low-quality counterfeits on the market.

When purchasing, you should check whether the appropriate certificates and other technical documentation are included with the device. It should be remembered that the basic rule for effective operation of the unit is complete tightness.

Another important parameter for the radiator is the amount of coolant in the vertical sections - the lithium-bromide mixture. A large volume may result in liquid overflow.

To assess the compliance of the volume, you need to focus on the sound that occurs when the unit rocks. It should resemble a soft rustling sound. If the sound of flowing liquid is clearly distinguishable, the radiator, with a high degree of probability, may turn out to be a handicraft fake.

European manufacturers provide a guarantee of up to 5 years for most of their models. Their prices are directly proportional to the number of sections and they are higher than for water analogues

On products manufactured using factory technology, the welding seams do not have any flaws, unlike units of unknown origin.

Manufacturers with a good reputation cover product bodies with high-quality powder paint. Therefore, the integrity of the paint layer is difficult to damage even when in contact with a solvent. You should not miss such a moment as the tightness of the filling valve.

DIY installation subtleties

Installing a vacuum radiator is not difficult, but in order to avoid any alterations, you need to learn a few rules. It is necessary to follow the recommendations regarding the placement of the unit relative to the wall, floor, and window sill.

At the same time, the distance between the radiator and the wall is at least 50 mm, between the device and the floor - from 20 to 50 mm, the optimal distance to the back of the window sill is 50-100 mm.

The photo shows options for connecting radiators. You should be aware that the inclusion of other heating devices in the heating circuit, along with vacuum ones, reduces its efficiency

The installation itself is not much different from inserting into the system radiators of other types. The only difference is that the entrance and exit are at the bottom.

Installation of a vacuum unit involves a chain of actions following each other:

1. Drain the coolant and dismantle the old heating device.
2. Mark the installation sites.
3. Attach the brackets. They are tested for stability and strength.
4. Ball valves are installed. Through them the device is connected to the main line. The joints must be sealed using tow or sealant.
5. Check the system for leaks.

To improve heat transfer, you can place a sheet of foil on the wall behind the radiator. If you have previously completed thermal insulation, you will have to increase the length of the brackets by an amount equal to the thickness of the thermal insulation layer. If the house is insulated, the efficiency of the heating system will increase.

The best manufacturers of vacuum radiators

Vacuum heating devices do not yet have a wide range of heating devices on the market. The company's products enjoy special authority among consumers. EnergyEco. This Russian manufacturer uses 1.5 mm steel to make batteries. Users note high-quality performance, good heat dissipation - about 170 kW per element.

The working pressure for the radiator is from 0.6 to 1.3 MPa. Even at 2 MPa the device can work, but 5 MPa is too much for it - it begins to collapse. The cost of a radiator from EnergyEko is considerable, but the demand for it does not fall.

Manufacturer Forevacuum produces vacuum devices of wall and baseboard type. The heat output of a register 1 m long at a coolant temperature of 50 °C is 239 W.

The thermosiphon register has a low metal consumption, since its thin-walled body is not designed for high internal pressure. At 50 °C and using ethanol it is only 0.027 MPa

You can also find Chinese-made radiators on the market.They will have a lower price, but sometimes of dubious quality. When purchasing, you should carefully inspect them and check the documentation.

Conclusions and useful video on the topic

Introduction to the design of a vacuum device and its operating principle:

Some craftsmen create vacuum batteries with their own hands:

There are conflicting opinions regarding the advisability of using vacuum radiators. But in some cases this heating method can be very effective. The main thing is to make sure when purchasing that they are of excellent quality and completely safe.

Do you have any questions, have you found any shortcomings, or would you like to add your own opinion to this material regarding vacuum heating radiators? Please leave your comments in the communication block located below the article.