Cast iron radiators: advantages and disadvantages,

How good are modern cast-iron radiators with alternative solutions? When is it justified to use them when installing the heating system? How much do they serve, and how much heat does it give? In our article we will try to answer these and many other questions.

Advantages and disadvantages

For a start, let's compare cast iron heating radiators with other heating devices competing with them on the modern market. So, how do their basic technical characteristics relate?

Please note: the values ​​are fairly arbitrary. The spread of characteristics between real devices is due to the size of the section, the thickness of its walls and the area of ​​the fins.

As is easy to see, the characteristics of cast iron batteries are not impressive: a fairly average heat transfer is adjacent to a low mechanical strength. Let's try to highlight the advantages and disadvantages of cast iron radiators.

pros

• Corrosion Resistance (including electrochemical). Cast iron tolerates prolonged contact with moist air or water saturated with oxygen. In addition, it does not form electroplating pairs with any of the metals used in the heating circuits. For comparison: steel registers do not tolerate the discharge of heating systems for the summer; Aluminum is actively destroyed in a common circuit with copper pipes or fittings.
• Durability. The lifetime of cast iron radiators of heating declared by the manufacturers is at least 25 years; in fact, the oldest cast-iron heating devices are already in the second century. As a rule, the motive for replacing them is changing aesthetic requirements or sludge compressed in sections, which is difficult to remove by ordinary washing.

• Low hydraulic resistance. The collectors and channels of the sections are wide enough so as not to delay the water flowing through them with minimal pressure. Due to this property, heating systems with cast-iron radiators can work not only with forced, but also with natural circulation - due to convection of water heated by the boiler.
• The large mass and solid internal volume of the section provide significant thermal inertia of the system.. Having warmed up, the contour will cool down slowly enough. This property is very useful when using a solid fuel boiler: the temperature drop in the room between the kindling will be minimal.
• Finally, the price of domestic iron section is significantly lower., than steel or bimetallic, and about the same level as aluminum.

To clarify: the production of cast iron radiators is established both in Russia itself and in neighboring countries. Logistics and customs duties can shift the balance of real prices in one direction or another.

Minuses

• Cast iron is relatively fragile. He is afraid not only of high internal pressure, but also of mechanical effects. However, this means mostly stringent requirements for loading equipment.

• Considerable mass and internal volume of sections have a reverse side: batteries are demanding on the quality of fasteners and can be mounted exclusively on the main wall.
• The appearance of modern cast iron batteries is far from the clumsy Soviet-style products, but still noticeably inferior to aluminum or bimetallic heating devices.

Weigh the pros and cons

Cast iron batteries are ideal for a stand-alone circuit with a solid fuel boiler. Heating of a summer house with cast iron radiators is a great idea, but I want to warn against their use in central heating systems, despite the long experience of using cast iron in this capacity.

Connection

Fitting

How to connect a cast iron battery with your own hands? Traditionally, connectors for the use of heaters are used on liners; The connection is ensured by a radiator plug and lock nut. Tightness of the connection gives the winding sanitary flax (preferably with paint or silicone sealant).

The installation instructions for the radiator are as follows:

1. The lock nut and the plug are successively screwed onto the long threads of the sleeves;
2. The radiator is hung in such a way that the liners are coaxial with its collectors and enter them by 2 - 3 centimeters.
3. Corks are rewound and driven by liner, screwed into the threads of the outer section.
4. Then they are tightened by the lock nuts - also, of course, with the winding.

Recently, however, for the installation of American women have been used more often - detachable fittings with cap nuts.

In this case, the installation looks different:

1. Crane with an American mounted on the liner coaxially collector battery.
2. Mate American is screwed into the radiator plug through passage.
3. The union nut is baited and tightened with a wrench with moderate force.

Useful stuff

When installing it is useful to remember a few things.

The efficiency of cast iron radiators (let's call it the ratio of their real thermal power to the nameplate) will be maximum with the following connection diagrams:

• With the number of sections up to 10 - side;
• With the number of sections over 10 - diagonal.

The silting of the battery can be avoided by connecting it in a bottom-up pattern. Continuous movement of the coolant through the lower collector will not allow sediment to linger in it. In other cases, it is advisable to provide the bottom blind plug with a flushing tap.

Please note: this applies to those cases where cast iron heating devices operate in the DH system. In the autonomous circuit, all suspensions are quickly collected in a mud tank and do not create problems in the future.

By the way, about the declared power: manufacturers give its values ​​for the temperature delta between the coolant and the air in a heated room at 70 degrees (for example, 90 / 20С). Reducing the delta twice entails, as is easy to guess, a two-fold drop in heat transfer.

Intersectional leaks

The main problem of cast iron batteries is intersectional leaks. Paronitic gaskets between the sections after numerous cycles of heating and cooling (and the accompanying expansion and contraction of sections) lose their elasticity, and the next time the temperature drops on one of the collectors, moisture acts.

The problem is solved in three ways:

• Resetting the heating system for the summer. The service life of cast iron radiators from contact with moist air is almost not reduced.
• Tightening problem nipple. To do this, with the circuit removed, a blind plug of the radiator is opened, and through it a radiator key is inserted into the collector - a steel bar flattened at one end. Nipple turns counterclockwise (on the side of the blind plug the thread is always left).
• With a large number of leaks, the radiator is completely relocated with the replacement of all gaskets. In the absence of commercially available paronitovyh products gaskets can be cut from an unwanted car camera.

After any depressurization, the cast-iron battery is necessarily checked under pressure or pressure-tested with a manual pump.

What is the pressure of pressure cast iron radiators in the domestic environment? As a rule, a little more working pressure circuit. For an autonomous system, 3 kgf / cm2 is sufficient, for DH, it is desirable to conduct tests at 6 kgf / cm2.

Conclusion

As you can see, despite their age, heating cast iron radiators remain in demand in modern heating systems. The video in this article will help the reader to learn more about their features. Successes!