Closed heating system with forced circulation

Comfort and wellbeing during the winter months depend on keeping your house warm and inviting. The kind of heating system you select is one of the most important factors in attaining effective heating. A closed heating system with forced circulation stands out among the available options as a dependable and efficient way to maintain ideal indoor temperatures.

Closed heating systems with forced circulation use pumps to guarantee a steady flow of heated water throughout your house, in contrast to open heating systems that rely on gravity to circulate water. More control over temperature distribution and the ability to personalize heating zones within your home are just two benefits of this method.

The boiler, which heats the water that will be circulated through the system of pipes installed in your home, is the central component of a closed heating system. Depending on your preferences and how your home is laid out, these pipes are positioned to distribute heat to underfloor heating systems, baseboard heaters, and radiators.

Reducing heat loss is one of the best things about a forced-circulation closed heating system. Closed systems keep the water contained within sealed pipes, eliminating energy waste and guaranteeing optimal efficiency in contrast to open systems, where water is exposed to the air and may lose heat through evaporation.

Advantages	Disadvantages
Efficient heat distribution	Requires electricity for circulation pump

Scheme of a closed heating system that has forced circulation

What is a closed heating system

Depending on how the expansion tank and outside air interact, the heating system can be either closed or open. The pump is used by the coolant to move around. The pump is a part of the hydraulic scheme, which makes the room heating much more efficient. and forced circulation makes it possible to include more heating elements in this kind of plan.

The power supply is what makes the pump’s existence necessary, but as a result, the coolant starts to circulate far more effectively. When putting such a plan into practice, the pump is installed in front of the boiler on the reverse tribe. There is also installed the expansion tank for heating a closed type.

The coolant in a closed heating system cannot evaporate. It follows that you do not always need to maintain its level under control in the system. You can adjust the temperature in a single room and warm up for a lot less time thanks to forced coolant circulation. Included in the indoor thermostat chain allows the room to be heated quite effectively in the event that the outside temperature falls below the predetermined level.

To put it briefly, a forced-air closed heating system is a wise choice for effectively heating your house. Closed systems keep the water sealed off to prevent any loss through evaporation or oxygenation, in contrast to open systems where the water comes into direct contact with the atmosphere. A pump forces heated water through pipes to provide even distribution throughout your home with forced circulation. Through the optimization of heat transfer, this technique not only keeps the area consistently warm but also lowers energy costs. Any home can benefit from the dependability and efficiency of a closed heating system with forced circulation, whether it’s for a warm winter or year-round comfort.

Elements of a closed -type heating circuit

The following components are part of a forced-circulation closed-type heating circuit:

• any type of boiler;
• circulation pump;
• the pipes necessary for the construction of carts, risers and jumpers;
• cork and ball valves;
• air vents;
• fixtures for fasteners;
• expansion hermetic tank of a membrane type;
• heating radiators;
• adapters necessary for connecting pipes;
• check valves;
• filters that are required to maintain the operation of the heating boiler and pumps.

Principle of operation

Coolants, such as water or antifreeze. heated using a boiler for heating. There is a sudden increase in volume when the temperature rises. The expansion boiler is filled with excess coolant. This unit has two compartments and looks like a capsule.

The liquid coolant enters the heating process in the first compartment, which is a hydraulic chamber. The gas chamber in the second compartment is pressurized with nitrogen.

Pressure, which is equivalent to hydrostatic pressure in the circuit, starts to be set before the tank’s heating process begins. The valve allows the coolant to enter the expansion tank while it is heating.

Because the gas chamber’s volume starts to decrease and the gas pressure rises as a result, it helps level the pressure inside the system. The same circulation pump returns coolant from the expansion tank to the system.

Features of the closed heating system scheme

Some features of a closed heating scheme. Along with the heating boiler, the expansion tank and the circulation pump may be located in the same room. There are some benefits to this feature, including a reduction in the overall length of pipelines and the elimination of the need to install large diameter pipes and adhere to installation tilt angles.

Furthermore, installing such equipment on a reverse trunk is the best option. If the coolant flows through the pump at a low temperature, it can run longer.

Small rooms can use the open-type heating scheme because it has certain dimensions restrictions. There are no such limitations with the closed heating system.

Pros and cons of a closed heating with forced circulation

Closed heating has benefits and drawbacks, but overall the benefits outweigh the drawbacks.

The following are some benefits of a closed system:

• Large heat transfer.
• The possibility of using smaller diameter pipes, which makes installation more economical. Pipes of the same length, but with a smaller diameter are much lower than pipes of larger diameter.
• Due to tightness, the likelihood of corrosion is reduced.
• Lack of evaporation of the coolant.
• The duration of the boiler is higher due to a decrease in the temperature difference at the output and input.
• The ability to use antifreeze as a coolant.
• The installation of such a system is simplified, so there is no need to calculate the length, height, slope and diameter of the pipes for heating with forced circulation .
• The scheme of the closed heating system saves heat, as a result, the fuel consumption decreases.

The following are some drawbacks of such a system:

• Energy dependence, t. e. For a circulation pump, power supply is necessary. To solve this problem, it is necessary to provide the heating system with a uninterrupted and independent source of electricity.
• The circulation pump itself is not very expensive, however, the installation of the system is quite expensive.
• For the operation of the pump, constant electricity costs are required.

Installation of a closed heating system

Selecting a boiler that satisfies the two requirements of view and power should come first in the installation process. Recently, solid fuel boilers have gained a lot of popularity. In use, they are far less expensive even though they are bulkier. Several things can impact the boiler’s power.

The circulation pump should be cut into the return to extend its lifespan. The issue is that water that has already been chilled is flowing through the opposite pipe. Rubber cuffs and seals are provided by the pump design. Rubber components are largely unaffected by chilled water that enters the return, which helps them to hold onto their original properties for an extended period of time.

Installing the system requires pipes with a minimum diameter. The volume of coolant that fills the system starts to decrease, which enables you to lower the cost of installing a forced circulation heating system. This has an impact on the heating boiler’s power and expansion tank selection. It is essential to add water to the closed heating system once the pipes and equipment have been installed.

Conclusion

Comparing closed systems with forced and natural circulation, we find that the differences between them are negligible. The extended equipment life and low installation costs are the only distinctions between a closed system and forced circulation.

What is noteworthy heating system with compulsory circulation of a closed type

Two-pipe system closed

Two types of autonomous heating systems exist. It can be either closed or open. The coolant circulation within the circuit, which can be forced or natural, is what makes them unique. In the first scenario, the laws of physics are the only factors influencing the flow of hot water through the pipeline. When building this system, the contours’ slight slope in the direction of the water movement is the only thing that needs to be considered. The forced circulation heating system is always of the closed type, and the circulation pump is integrated into it. Although this design is more complicated, it works much better.

Features of forced circulation

The second iteration of the heating system, which involves forced coolant circulation, is the one we are interested in. It is energy-dependent in the first place because the pump can only operate on an AC network. The device will shut off if the electricity is cut off, so you will need to make sure the heating is maintained in the regular mode.

How am I going to accomplish that?

1. Purchase a gas generator and keep it for such cases.
2. Install the bypass, which will cut off the circulation pump and transfer the system to the natural movement of hot water. But since we are talking about a closed scheme, this jumper may not help in some wires. So the first solution to the problem is better.

An open and closed heating system: what is it? Although the second example’s name already implies that the coolant is in contact with the air, the first example’s does not. The expansion tank is the point of contact. It may be totally sealed or left open. The second design is a container with a membrane installed inside that uses gas uploaded inside to maintain pressure.

Hot water will gradually lose volume due to evaporation caused by the open design. This is a minor drawback, but not by much. The only person who will need to regularly refill the heating system’s cold water supply is the home’s owner. If you use the water supply network as the feed, it is relatively easy to accomplish by hand.

Why is a circulation pump necessary?

It all comes down to how evenly coolant is distributed through radiators. This is particularly valid for a system like the one-pipe system. This is an illustration of a Leningradka scheme. This is a ring-shaped installation that has a heating boiler installed in the center. Everything is very basic; there are no risers or intricate pipe wiring.

Radiators crash into a pipe that runs from the boiler into each room. The pipe almost reaches the floor. You can save money on materials and streamline the installation process by using a one-pipe scheme. However, she has a major flaw in that the Leningrad system does not distribute hot water evenly throughout the batteries. Because the coolant in those installed closer to the boiler is hotter, they absorb more thermal energy. A portion of the heat stays in this location, and the remaining portion, along with the coolant, travels to the next devices at a reduced temperature.

You are unable to heat the house’s interior evenly with such a distribution. Additionally, the room will be colder in the winter the further it is from the boiler. It is the established circulation pump that solves this problem. As a result of the slight pressure it produces, the coolant starts to flow through the circuit at a specific rate. Enough hot water is supplied to all the heating radiators in an even manner.

Take note! The location of the circulation pump installation is on the reverse circuit close to the boiler. Why does it matter so much? The coolant in this circuit is the coldest, which is the problem. The circulation pump’s design includes rubber gaskets and cuffs, which quickly break down in the presence of hot water. As a result, the location with the lowest coolant temperature is chosen. This is where the expansion tank is located, by the way.

Two-pipe forced-circulation heating systems with coolant are not unusual. Additionally, even though natural circulation is used the majority of the time, certain additions are required, which the circulation pump takes into account depending on the size of the house. Without it, the task of distributing hot water throughout the rooms consistently will be extremely challenging, and in certain situations, unfeasible. This is particularly true for multistory buildings, as natural circulation will not be able to raise the necessary hot water levels, say to the second floor, to the required level.

Features of the mounting process

• In a closed -type heating system, you can use pipes with a minimum diameter. This is a big plus in terms of saving materials spent on the heating system. This also explains the convenience of installation, especially if the assembly is made with your own hands.

A significant volume of water is required for heating with natural circulation in order for it to progress under the influence of temperature in a pipe interchange. In other words, we raise the fluid duct’s velocity by decreasing the pipes’ resistance. Large diameter pipes are not required in a system with forced circulation of the closed type since the pump is already operating at this speed, negating the need to establish a flow velocity.

• The volume of the coolant also affects the volume of the expansion tank, which should be 10% of the capacity of the entire heating system. In a closed -type heating, a smaller expansion tank can be installed. And this is a decrease in the cost of buying a more expensive device.
• In a closed -type heating – it will not be so important whether it will be one -pipe or two -pipe – it is recommended to install boilers with modern automation. It is she who will be able to clearly control and regulate all passing processes.

In addition, a lot of manufacturers have sensors that track the coolant’s temperature and speed. The anti-bunch sensor, which cuts off the fuel supply to the combustion chamber when the hot water in the circuit reaches a boiling point, deserves special attention.

Inside the circuit, there are anti-frustration sensors that keep the temperature within the contour at least +5C. Installed sensors periodically activate the circulation pump when the heating system is shut down for an extended period of time. This is required to prevent the water pump stator from jamming during the starting process.

We also add that, thanks to automation, you can fully regulate the fuel supply based on outside or inside room temperatures. This enables you to schedule the entire temperature regime for a specific amount of time, say a few days or a week.

How to choose the right circulation pump

The cost and simplicity of use and maintenance are the two primary factors that are typically taken into consideration when choosing a circulation pump. Nonetheless, the size of the heated house affects a number of technical features.

Here are a few of them:

• The area of a private country house is 250 m². It requires a pump with a capacity of at least 3.5 m³/h and pressure 0.4 atm. Although with pressure you must be careful. Sometimes a powerful pump has a small pressure that is not enough to raise the coolant to the desired floor. Therefore, our tips are exclusively advisory in nature.
• Area 250-350 m². The power of the pump should be at least 4.5 m³/h, and the pressure – 0.6 atm.
• Area 350-800 m². Power – 11 m³/h and pressure 0.8 atm.

By the way, a forced-circulation single-pipe heating system can use the indicators we recommend. Such a pump in particular will function well in the Leningradka scheme.

Of course, a variety of indicators must be considered in order to select pumping equipment with accuracy. As an illustration, consider the length of the heating contours, the quantity and type of radiators, the boiler’s power, the installed pipes’ diameter and material, and the presence of shut-off valves. The decision is influenced even by the fuel type used. Therefore, you should not make this decision on your own; instead, let experts handle it.

Be aware that air traffic jams, which form in radiators, risers, and horizontal contours, will be impeded by the circulation pump’s regular operation. Maevsky’s taps on radiators, automatic air vents, and other devices are installed in order to get rid of them. Their existence in contemporary heating networks serves as an assurance of the overall system’s quality.

Conclusion on the topic

To what extent is the forced coolant circulation system justified? Experts all agree that she operates with extreme efficiency. However, the scheme’s energy dependence makes it less appealing. First of all, these are extra accounts for the purpose of paying for electricity. Secondly, these are issues with electricity shutting off for unclear reasons.

Keep in mind that the circulation pump is a low-power appliance with minimal electricity consumption. Still, consumes. We have already discussed how to address the second issue, so we won’t reiterate it here. Permit these two drawbacks to exist since nothing would exist without them. However, they totally outweigh the benefits of all heating operating efficiently. As a result, ignore problems and try not to let them get to you too much.

Closed heating system – Scheme with examples

A heating system is made up of numerous components that are linked together via a pipeline to form a single circuit. Here, the coolant—which is often fluid—is constantly moving, which causes heating. An expansion tank is used in a closed heating system to counteract the phenomenon of coolant expanding when heated. These devices fall into one of two categories, depending on whether the system is closed or open. A closed heating system has a tank that is isolated from the outside world, whereas an open heating system has a tank that is in contact with the air.

Pumps are used in closed heating systems to circulate coolant, ensuring that the fluid is kept at a sufficient level throughout the system. By adjusting the coolant’s speed, pumps enable the closed system to operate far more effectively (see "A closed and open heating system with examples of the circuit").

Forced circulation is also good in that additional contours with connected heating devices can be connected to such a system. Of course, such systems become energy -dependent, since the functioning of the pumps requires electricity, but this deficiency is compensated by high efficiency of the entire structure.
Pumps in a closed heating system is mounted on the return pipe immediately in front of the boiler. In the same place you can place an expansion tank. The closed heating system has a number of advantages that become obvious when comparing with other types of heating systems: the system is installed without much difficulty, since there is no need to observe a constant slope. The pipeline does not need insulation, and the pipeline itself can be done thinner, which will affect not only its aesthetic qualities, but also on the cost of the structure.

You won’t need to check the coolant level as frequently in a closed heating system because it can’t evaporate. Moreover, circulation pumps speed up the process of warming up the rooms, and thermostats installed in the circuit allow you to precisely adjust the temperature throughout the house.

Elements of a closed type heating system

There are numerous components in the closed heating system’s circuit, including:

• boiler;
• membrane expansion tank;
• circulation pump;
• heating devices;
• pipes for laying the circuit, installing risers and carts;
• fitting;
• taps;
• filters;
• Fasteners.

The principle of operation of a closed heating system

After being heated in the boiler, the coolant travels through the pipeline and heat-distributing devices. An expansion tank enters the system to hold extra fluid when the coolant completely fills the circuit. The membrane expansion tank is made up of two cavities, one of which is filled with gas or air and the other with additional coolant. Also see: "The heating skirting system is innovative and useful."

A pressure is produced during installation in a closed heating system, and this pressure further establishes the pressure throughout the contour. The coolant’s heating causes the system’s pressure to rise. The excess pressure that results from this rise enters the tank and bends the membrane inside. The circulation pump is the next stop on the coolant’s path, and the system operates normally after that.

Features of the closed heating system scheme

A forced-circulation closed heating system has the following characteristics:

1. The possibility of installing an expansion tank and a circulation pump near the heating boiler, which allows you to reduce the costs of pipes and simplifies the installation of the entire system.
2. The full tightness of the tank leads to the fact that the coolant cannot evaporate from the system, and the pipeline itself is reliably protected from air entering.
3. Install an expansion tank and pump on the return pipe. The operation of the pump is possible only when a liquid has a low temperature passes through it.
4. Compared to the open heating system, the closed can be located in premises of any area.

Pros and cons of a closed heating system

There are benefits and drawbacks to the closed heating system circuit where the coolant is forced through. Less negative information is present, but when it is, it can be very important.

An enclosed heating system’s benefits include:

• high efficiency;
• the impossibility of evaporation of fluid;
• the use of pipe of reduced diameter;
• increasing the life of the boiler due to the temperature difference on the supply and reverse contours;
• decrease in corrosive influence on the pipeline;
• The possibility of using antifreeze.

The drawbacks of a sealed heating system include:

• Dependence on electricity, especially in regions where interruptions in electricity are not uncommon;
• the need to install a more complex, spacious and expensive expansion tank.

Converting the open system into a closed

The only reason a closed heating system with natural coolant circulation is used occasionally is due to its characteristics. What features are we discussing, and how does switching from one kind of system to another work? It is uncommon to consider switching from an open heating system to a closed system when installing one, but it is not difficult to accomplish. All that is needed is the installation of a membrane expansion tank, which will cause the design to become closed right away.

Of course, there is always the opportunity to design a similar scheme, but it will have some disadvantages of two types of systems. To ensure the natural movement of the coolant, the pipeline must be laid in compliance with a constant slope, which often leads to the appearance of air plugs and significantly complicates the installation.
What are the advantages of this design? Independence from electricity in this case is the only plus, but its need can be questioned: as a rule, in most houses there is always electricity. The cost of the pump and the operating costs associated with its use are quite low, so the classic closed scheme is still much better than open.

Installing a forced-air closed heating system has many advantages for homeowners looking for economical and reliable heating solutions. This system keeps the heating fluid contained within a closed loop, reducing heat loss and guaranteeing constant warmth throughout the house.

The ability of a closed heating system to maintain ideal temperature levels with forced circulation is one of its main benefits. Pumps are utilized to efficiently circulate the heated fluid throughout the house, ensuring even heating throughout. This not only makes the home more comfortable, but it also uses less energy, saving the homeowner money.

A closed system with forced circulation not only provides increased heating efficiency but also more control and customization possibilities. Homeowners can effortlessly control the temperature in various areas of their home, guaranteeing customized comfort levels for every living area. This adaptability is especially useful for multi-story buildings or larger homes where different rooms may have different heating requirements.

In addition, the system’s closed design guards against corrosion and contamination, extending the heating equipment’s life and lowering maintenance needs. Over time, fewer repairs and replacements are necessary because the risk of damage and deterioration is greatly decreased when exposure to external elements, such as air and debris, is eliminated.

All things considered, installing a forced-circulation closed heating system is a wise investment for homeowners trying to maximize their heating infrastructure. Long-term comfort, financial savings, and peace of mind are all provided by this system’s energy-efficient operation, accurate temperature control, and durability.

Video on the topic

The principle of heating