One -pipe water heating system with forced and natural circulation

Any homeowner should prioritize effectively and efficiently heating their home, especially during the cold winter months. Knowing the various varieties of heating systems that are available and how they operate is essential to having a well-functioning system. We’ll delve into the topic of one-pipe water heating systems in this article and examine forced and natural circulation techniques.

Because of their dependability and simplicity, one-pipe water heating systems are a common option in many homes. One pipe is used to transfer hot water from the boiler to the radiators and back to the boiler for reheating in a one-pipe system, as opposed to more intricate two-pipe systems that use separate pipes for supply and return.

One-pipe water heating systems frequently employ forced circulation as a technique to guarantee effective heat distribution throughout the house. To move hot water from the boiler through the pipes and into the radiators in this configuration, a pump is used. This continuous circulation ensures that each room has a constant temperature, which maximizes occupant comfort.

In contrast, natural circulation disperses heat naturally without the use of a pump by using the convection principle. A natural flow is created throughout the system as hot water rises in the pipes and pushes out cooler water. Because it doesn’t need a pump, this method can be less energy-intensive, but it might not work as well in larger or multi-story homes.

For homeowners trying to maximize their heating arrangement, it is imperative that they comprehend the distinctions between forced and natural circulation in one-pipe water heating systems. During the winter months, you can ensure effective heat distribution and reduce energy costs by selecting the appropriate system based on the size and layout of your home.

Device and principle of distribution of the coolant

Since heated water is supplied and exits heating radiators via a single collector, the system is known as one-pipe. All batteries connected to the main branch share a common pipeline. That is, as demonstrated by the example of the heat supply scheme for a one-story building, the input and output eyelcasting of each heating device are connected to a single pipe.

The one-pipe radiator heating system operates as follows:

1. The warmed coolant coming from the boiler reaches the first battery and is divided by a tee of two unequal streams. The bulk of the water continues to move directly along the highway, a smaller part flows into a radiator (approximately 1/3).
2. Having giving heat to the walls of the battery and cooling at 10-15 ° C (depending on the power and real return of the radiator), the small stream through the outgoing pipe returns to the common manifold.
3. Mixing with the main stream, the cooled coolant reduces its temperature by 0.5-1.5 degrees. Mixed water is delivered to the next heating device, where the cycle of heat transfer and cooling of the main flow is repeated.
4. As a result, each subsequent battery receives a coolant with a lower temperature. At the end, the cooled water goes back to the boiler along the same highway.

A crucial aspect. The radiator’s size must be much smaller than the distributing pipe’s diameter for the heating scheme to function steadily. For vertical risers with an upper outlet, where gravity facilitates the coolant’s flow downward, this rule does not apply (see the section below on system types).

Less heat reaches the final heaters the lower the temperature of the circulating water. There are three methods to solve the issue:

• At the end of the highway, high -power batteries are placed – the number of sections is increased or the area of panel steel radiators increases;
• by increasing the diameter of the pipe and productivity of the pump, the flow rate of the coolant through the main collector increases;
• combination of the two previous options.

The primary distinction between one-pipe wiring and the remaining two-pipe systems, in which the coolant supply and return are arranged according to two distinct branches, is the connection of radiators to a single distribution line.

Schemes of single -pipe systems

There are just two kinds of single-pipe schemes utilized for the heating of multi-story buildings’ apartments and suburban cottages:

1. The classic Leningrad heating system with lower horizontal wiring is presented above in the first picture.
2. Radiator network with vertical risers.

Radiators can be connected to the common ring line, which is positioned horizontally above the floor, using "Leningradka." The lower lateral accession of both carts is a genre classic. The installers use both of the more recent approaches, in which the pipes are connected to the battery diagonally.

Two-story and multi-apartment private homes use the second scheme. Batteries are fastened to vertical single risers that traverse the floors on each floor. Either the upper or lower horizontal collector supplies water to the risers.

Please take note that the "Leningradka" general line with horizontal lower wiring is a single pipe whose diameter does not vary over time. There are jumpers, or bypasses, on one-pipe risers that allow some coolant to flow past the batteries.

With both artificial and natural water circulation (gravity), both forms of turning are possible. Schemes are changed in response to operating circumstances:

1. For the work of Leningradka, in a gravity mode, you will have to increase the internal section of the ring collector to 40-50 mm, make slopes and raise the vertical acceleration of the accelerated area from the boiler, otherwise the duct will not be through the radiators. The open expansion tank is connected to the highest point, as shown on the fundamental heating scheme of one -story house.
2. Implementing the gravity principle in a two -story building is better according to the scheme with risers passing through the necessary rooms. The feed pipe Ø40-50 mm rises directly to the expansion capacity installed in the attic. Horizontal branches with slopes diverge from it, supplying water to the risers and radiators on top. On the rise, you can mount a bypass node with a circulation pump.
3. Closed single -circuit wiring with pressure circulation is presented at the beginning of this section. In the two -story house "Leningradka" it is necessary to make a double -circuit – provide a separate horizontal loop with the supply of the coolant through the ceiling, as shown in the axonometric scheme.

The Leningrad system was originally intended to be an inexpensive means of supplying heat to convection heating appliances. However, a tiny circuit with heated water can be connected to the highway if desired. In order to control the water temperature, you’ll need a three-way valve, a reverse, and an additional circulation pump.

Vital. At the end of the highway, behind the final radiator, the floor heating outline is permitted to be attached. One requirement is to make sure the collector is consuming the necessary amount of heat carriers, which means enlarging the diameter and boosting the main pump’s efficiency. If not, some of the heat from the batteries will be absorbed by the warm floor.

Comparison at the price of installation

One-pipe heating network adherents like to emphasize how inexpensive this kind of wiring is. The savings over a two-pipe system can be justified by using half as many pipes. We declare the following to be true: If you solder the heating from polypropylene, lentingradka will work out less expensive than a dead end system in one particular situation.

We use calculations to support our claims. As an example, we’ll use a one-story house with plan dimensions of 10 x 10 m = 100 m². We use the Leningradka layout on the drawing, figure out the pipe fittings, and create a similar perimeter around the dead end.

Thus, the following is required for the one-pipe heating device:

• Du20 pipe on the collector (outside Ø25 mm) – 40 m;
• tr. DU25 Ø32 mm on the return – 10 m;
• tr. DU10 Ø16 mm for eyeliner – 8 m;
• The tee of 25 x 25 x 16 (external size) – 16 pieces;
• tee 25 x 25 x 20 – 1 pc.

Referred to: It is not possible to complete the return walk along the corridor. The ring line’s cross section will then need to be increased for nine radiators to match the DU25’s external measurement of 32 mm.

We will determine the requirements for pipes and fittings for a two-pipe network by concentrating on the following layout:

• tr. DU15 Ø20 mm – 68 meters (highways);
• tr. DU10 Ø16 mm – 22 m (eyeliner eyeliner);
• tee 20 x 20 x 16 mm – 16 pcs.

Here are the current costs for plumbing fittings and pipes made of three materials from reputable manufacturers: stitched PEX polyethylene, PEX-PEX metal-plastic, and reinforced polypropylene (PP-R). The following table will contain the computation results:

Note: Assuming you are putting together the system by hand, we do not account for the cost of batteries, radiator cranes, or the installation of a single "Leningradka" pipe. The price is expressed in Russian Federation rubles, but this fact has no bearing on the final cost; it is the same for all nations.

As you can see, the price of the polypropylene pipes and tees is nearly the same for both schemes; the shoulder cost 330 rubles more than the other. In other materials, two-pipe wiring is unquestionably superior. The diameters are the cause; pipes with a wider cross section cost significantly more than pipes with "running" dimensions of 16 and 20 mm.

You can compute using less expensive plumbing from different manufacturers; the ratio is probably not going to alter. Please take note that since we are unsure of the precise number, we neglected to turn the pipes and the other little items with the 90° bouncers. The price of Leningradka will go up even more if every material is carefully calculated. The specialist demonstrating the computations in the video arrived at comparable findings:

In our article on the one-pipe water heating system with forced and natural circulation, we dive into an efficient and practical method for heating homes. Unlike traditional two-pipe systems, this setup simplifies installation and maintenance while still ensuring effective warmth throughout the house. By harnessing both forced and natural circulation, this system optimizes energy usage, keeping utility costs in check while providing consistent comfort. We"ll explore the principles behind this system, its components, advantages, and considerations for implementation, empowering homeowners to make informed decisions about their heating solutions. Whether you"re upgrading an existing system or exploring options for a new build, understanding the ins and outs of this one-pipe setup can lead to a cozy, cost-effective home.

Pros and cons of one -pipe turning

We will attempt to provide an unbiased evaluation and emphasize the true benefits of single-pipe water systems:

1. A closed scheme with a membrane expansion tank is easier to mount. One pipe is laid faster than two.
2. A single highway or a riser is easier to hide in the walls than two -pipe branches (example below in the photo). A spoon of tar: the ring manifold crosses the doorways that make the gasket difficult.
3. The heating network with risers is indispensable when it is necessary to organize a gear in the building for 2-3 floors. It makes no sense to pass through the overlap with two pipelines, one vertical line is quite enough.
4. Installation costs cheaply in one case: when the gravity scheme of the heating system is used in a one -story private house. Savings are achieved by laying one highway instead of two (remember, for the very a priori you need pipes of large diameters Ø48-57 mm).
5. The closed system is automatically regulated by means of radiator thermostatic valves. Reservation: it is necessary to take into account the specifics of the operation of heating devices and choose the right reinforcement. Below we will return to this issue.

Note: The benefits of this scheme cannot be directly linked to the location of warm floors. The two-pipe wiring is similarly straightforwardly connected to the heating circuit.

"Leningradka"’sprimaryissue is the coolant’s loss of heat as it travels to far-off batteries. It is not feasible to expand the radiator and highway sections indefinitely; four to five devices is the ideal number. in a single circuit.

We enumerate additional drawbacks:

1. Hydraulic instability – the influence of one battery on the work of the rest. If you block the first radiator valve, subsequent devices will receive hotter water and will overheat the rooms.
2. In order for the coolant to flow well into radiators with a closed Leningrad scheme, it is necessary to use full -pass reinforcement on branches. An increase in the hydraulic resistance of the eyeliner makes the water flow further in a straight line, the flow rate of the coolant through the battery decreases.
3. "Leningradka" and vertical wiring is more expensive than a two -pipe shoulder scheme. If you add the costs of additional radiator sections, then the cost of installation from stitched polyethylene is compared with the radial system where the fittings are not used, but there is a distribution comb.
4. The scheme is complicated in the calculation and tuning (balancing). The power and surface area of the heat transfer of the batteries must be determined as accurately as possible.

Large diameter pipes laid with a slope of three to five millimeters per linear meter is another drawback of the gravity turning. The room interiors are ruined by the risers that protrude from the ceilings. Plumbing pipelines into walls isn’t always an option; sometimes you have to get creative and build ornamental boxes instead.

Tips for choosing pipes and connection diameters

It is possible to design and install a heating option for a single pupil without the need for intricate hydraulic calculations. We make the process easier and provide helpful advice for setting up single-circuit systems:

1. The maximum number of heating devices on one loop of closed "Leningradka" is 5 pcs. To deliver the desired volume of the coolant to the batteries, enough pipe Ø25 mm (DU20). We make eyeliners from the pipe Ø16 mm.
2. If, for objective reasons, the number of radiators on 1 ring of a closed system must be increased, the cross section of the highway is increased to a diameter of 32 mm (DU25), eyeliner – up to 20 mm. It is economically impractical to put one pipeline on one pipeline, it is cheaper to lay 2 smaller lines.
3. The minimum diameter of the horizontal collector with natural circulation is DU40, the outer – Ø48 mm. In a two -story house, an accelerated riser and the beginning of distributing branches is made of pipe D50 (Ø57 mm), remote areas are reduced to the size of DU32. Vertical lines to radiators – DU20–25 depending on the thermal power of the heaters.
4. To automatically regulate heat transfer, select full -pass valves with thermal heads. In standard radiator valves, the hole is too small.
5. Connection to a wall or floor gas boiler is made according to a standard diagram shown below in the picture. A binding of an electric water device is made in a similar way.
6. It is better to attach to the solid fuel boiler "Leningradka" through a three -way mixing valve and buffer capacity. Since there is too little coolant in the system, there is a risk of overheating and boiling. Summary wiring containing more than 200 liters of water, it is allowed to be connected to a tt-boiler directly.

Vital elucidation. In the process of building the heat supply network’s housing, PN 22–28 polypropylene pipes reinforced with fiberglass, aluminum foil, or basalt fiber are frequently utilized. The STABI PPR-pipe variety has a minimum external diameter of 20 mm and no 16 mm size. As a result, radiator eyeliners have a 20 x 2.8 mm cross section.

If you use one-pipe wiring wisely, the listed recommendations will assist in organizing heating properly. In the upcoming video, common errors and queries about installing Leningradka watches are analyzed.

Selecting an appropriate heating system for your house is essential for both energy efficiency and comfort. It’s crucial to think about the argument between forced and natural circulation one-pipe water heating systems. Although each system has benefits and drawbacks, the decision ultimately comes down to your unique requirements and situation.

Forced circulation one-pipe water heating systems provide effective heat distribution, guaranteeing constant warmth throughout your house. By actively forcing hot water through the pipes, the forced circulation mechanism heats the water quickly and keeps it at a constant temperature. Larger homes or buildings where rapid heating is required to maintain comfort may find this especially helpful.

Conversely, natural circulation one-pipe water heating systems don’t require any extra mechanical parts to function. Rather, they depend on the hot water’s inherent buoyancy to move through the system. In the long run, this can be more economical and energy-efficient than forced circulation systems, even though it may result in slower heating, particularly for smaller residential properties.

A few important things to think about when choosing between these two systems are your home’s size, your budget, and your environmental impact. Larger homes or structures where quick heating is required might benefit more from forced circulation systems, whereas smaller properties might benefit from natural circulation systems’ lower costs and higher energy efficiency.

In the end, seeking advice from a qualified heating and insulation specialist can assist you in making an informed choice that takes into account your unique requirements and situation. Through meticulous consideration of the benefits and drawbacks of every system, you can guarantee that your house is outfitted with the best heating option for maximum efficiency and comfort.

Video on the topic

Differences in single -pipe systems with natural and artificial circulation

Hydraulic paradox in the heating system. Riddle No. 4

The role of slopes and the expansion tank in the gravitational pipe system of heating