Diagrams for connecting radiators to the heating system

Recommendation points

• Bottom connection of radiators
• Diagonal connection for two-pipe system
• Diagonal connection for one-pipe distribution
• One-way connection

An important issue when installing heating in a house is the choice of a radiator connection diagram. Having made the right decision, you will optimize heating costs, both during installation and operation of the equipment. It is important that the radiator connection diagram is correctly matched to your home heating system.

Bottom connection of radiators

With this connection, the supply pipe, like the return pipe, goes into the bottom plugs of the battery. The coolant has a priority direction of movement along the lower collector. Additional heat exchange is carried out due to the fact that the heated coolant rises up the radiator. Such a scheme is the least expensive in terms of materials, and it is convenient to perform it even when doing work with your own hands in “one hand”.

Most often, such a scheme is used when installing a one-pipe heating system, it allows you to quietly run a pipe, and when laying the main pipe on the floor, leave only short pipes for connecting the battery in sight.

One significant disadvantage of such a connection of radiators is the reduced efficiency of heat transfer compared to a diagonal connection on a two-pipe system. The difference is about 12-15%.

However, it should be noted that when installing heating in a small house with a small budget, including heating, the use of this scheme is justified, and in the future you will never think about these percentages. The scheme is reliable, time-tested and serves faithfully for more than one generation of private house owners.

In our opinion, the scheme is not acceptable when heating without a pump. Another of its features should be noted the need to perform on a single-pipe system “brakes” under the radiator, sections of narrowing the diameter of the main pipe between two points of the tie. This constriction allows the flow of the coolant to be redirected through the radiator rather than past it. However, as already mentioned, you should not use such a scheme with a significant length of the heating system pipeline..

It is possible to use a similar scheme with two-pipe wiring, however, here the connection scheme loses its advantages while maintaining the disadvantages.

Diagonal connection for two-pipe system

The most correct from the point of view of heat transfer is heating, made in a two-pipe design, with diagonal connection of radiators. The supply pipe is connected to the upper plug, and the return pipe to the lower one, on the opposite side. Such a system is taken in calculations as 100% efficiency. But among others, this is a more expensive system in terms of materials and execution time..

With a diagonal connection, the hot coolant at the radiator inlet and along the upper collector meets the room air already heated in the lower parts of the radiator and heats it up to a higher temperature. Thus, the heat transferred from the heat carrier (water) to the air in the house is used with the greatest efficiency..

A minor drawback of this connection system, as mentioned above, will be the impossibility of adding additional sections without cutting the pipes and re-welding them. However, with a careful calculation of the number of radiators at the stage of system design, this disadvantage can be ignored..

The diagonal connection has proven itself excellently when working with forced circulation and with self-circulation. In systems operating on natural circulation, diagonal wiring makes it possible to abandon the installation of temperature control valves, which reduces the hydraulic resistance of the pipeline system and has a positive effect on the operation of the system. True, radiator taps with minimal resistance are currently available, and we recommend installing them for ease of maintenance.

Of course, the diagonal connection of heating batteries is the most desirable, but this is not always unambiguously possible..

Diagonal connection for one-pipe distribution

In this way, they are trying to get away from those 12-15% decrease in the efficiency of heat transfer with the lower wiring. Connection is made to the upper radiator plug and to the opposite lower plug while maintaining the sequence of connecting the batteries in the circuit.

The use of a diagonal connection of radiators on a one-pipe system does not give the advantages that it has when performed on a two-pipe wiring. The skew in heat transfer and coolant temperature increases significantly along the contour. In fact, most of the heat is discharged in the first heat exchangers. Even the presence of a bypass will no longer correct the situation.

One-way connection

It is a worthy alternative to the diagonal connection and has its own characteristics. The supply pipe enters the upper radiator plug, and the return pipe enters the lower one on the same side. The efficiency of such a connection is 2-7% lower than the diagonal one.

1. Two-pipe wiring. 2. One-pipe wiring

This connection is often used in heating systems with risers running from one floor to another. Many people use it when it is not possible to install the proper number of battery sections already during the initial installation, and it is expected to increase their number in the future. One-sided connection allows at any time, in the presence of shut-off valves, to add a certain number of sections.