Heat transfer of cast iron radiators: features of the

The classic cast-iron accordion, like nostalgia for childhood, still stands firmly among the variety of aluminum and bimetallic radiators, halogens and convectors. Although heat dissipation of cast iron radiators is lower than that of many modern heaters, but legends about its durability and unpretentiousness go on the open spaces of the former Union. The correct calculation of the number of sections and people's ingenuity allows you to increase the power of the "cast iron" and create a warm atmosphere indoors.

Classic retro

With the onset of cold weather, heating radiators become the focus of increased attention of apartment dwellers and the starting point of dialogues. Why is it warm in a house with centralized heating and not so much in the next? What does the temperature of cast iron batteries and, accordingly, the degree of your positive and what they are generally attractive?

Where is plus and minus

Contrary to the temptations of the modern market for heating devices, cast iron batteries are good:

• long service up to half a century;
• corrosion resistant;
• lack of a scum thanks to the increased diameter of channels;
• the ability to vary the number of sections;
• low hydraulic resistance;
• high power;
• the concentration of heat due to the considerable thickness of the walls and the volume of water inside;
• decorative and floor installation (modern samples);
• different cost - the price can vary from 400 to 6000 rubles.

The accumulation of rust over time can not be called a significant drawback of the product, but here it is worth looking closely at the following:

• they are heavy. They are simply very heavy, and if one section weighs between 6 and 7 kg, you will need a dozen of them, and not even in one room, but plus the weight of the volume of water (1.35 liters);
• small heat transfer surface and low thermal conductivity of the material;
• heat propagation occurs by radiation, and only 20% by convection;
• poor compatibility with heating systems already equipped with thermal control devices, and this eliminates fuel economy.

The traditional “cast iron” MS-140, intended for heating the residential sector, served as the basis for the emergence of new models - MS-140-500, MS-140-300, MS 140-180. They differ in mass, capacity, intership distance, etc.

Calculator in your hands

The most important indicator of any battery for the consumer is its power or heat transfer - the allocated amount of heat for a certain period of time. Knowing what heat transfer from cast iron radiators, you literally do not overload the house / apartment and do not arrange Africa.

Several factors will affect the calculation of heating parameters:

• number of windows;
• ceiling height;
• room area;
• number of exterior walls;
• maximum subzero temperature in the region.

Calculated the required power in several ways, among which you can choose the least confusing and convenient.

Note! Do not be afraid if you get a fractional number as a result of mathematical operations. Round it up in a big way - a small “re” is always better than a small “not before”.

Elementary Watson

The basis for this calculation is an external wall with windows in a panel house (SNiP II-3-79). If your room has 1 wall with 1 window, then for every 10 m2 you will need 1 kW of radiator power. Two exterior walls will increase the power rating to 1.3 kW.

The second simple way to calculate the area of ​​the room with a ceiling height of at least 2.5 m, which is enough 100 watts per square.

The formula has the following form:

S * 100 = N total, where

• S - area of ​​the room (length * width);
• N total - the total heating capacity.

The nominal heat output of the cast iron radiator section is on average 140 W and, by dividing Ntot by this figure, you can find out the required number of sections.

By volume

In this case, the following formula is used for mathematical operations:

h * s * Nm = N total, where

• h is the ceiling height;
• S is the area of ​​the room;
• Nm is the standard power rating per 1 m3, which is on average 41 W / m3.

Note! With proper insulation and the presence of double-glazed windows, the rate of thermal power is reduced from 41 to 34 W per m 3.

If someone forgot physics, the expression h * S can be replaced by the symbol V, which means the same volume - width * length * height. In this case, the formula will have the same value, but look shorter:

V * Nm = N total

Heat transfer of one section of the cast-iron radiator is calculated similarly to the above method: Ntotal / 140 W. Again, we should not forget that the proposed calculations are based on an average of +20 ° C indoors and minus the same on the street. Therefore you should not discount the climate zone in which the radiator should provide you comfort.

Note! If the room is angular or with a balcony, then 20% is added to the calculated power (N total). For living rooms, the resulting indicator of the number of battery sections is rounded up, for the kitchen - into a smaller one.

Nota bene

Since radiator tests take place under laboratory conditions, some data may differ during operation. For example, the declared heat transfer rate of 1 section of a pig-iron radiator to 160 W at a real coolant temperature in the system from 60 to 70 ° C will significantly decrease.

Thermal insulation of problem areas, especially in a private house that is on the ground, will save you warm:

• 200 W in the area of ​​the entrance / balcony door;
• 100 W in the window area.

Note! Do not chase for exotic, but cheap products. If the capacity of the section, the thread of the nipple hole, the heat transfer of the cast-iron radiator ms 140 is indicated by the Russian / Belarusian manufacturer, then, for example, the “Chinese” may not have such information. It’s hard to imagine what you risk.

Innocent Tricks

A few simple tricks will help increase radiator heat dissipation:

• Constant adherence to the purity of the surface of the product - dust, especially between the sections, significantly impairs the heat exchange process;
• correctly paint the surface - remove the old layer, degrease, apply a primer (GF-021), paint (PF, MA);

Note! These oil enamels are given as the most affordable and optimal. The instructions on the bank will help you choose special funds.

• install a heat-reflecting foil screen behind the radiator - this will be especially effective on the outer wall;
• check the “insides” of the product for burrs, which may appear after being connected to the system, it is for them that the fractions of the garbage will cling, accumulate;
• if you do the installation yourself, do not allow the battery to skew - it will thoroughly interfere with the circulation of the coolant;
• adhere to the standard parameters for placing the battery against the wall, window sill;
• Do not block the flow of warm air with furniture, screens.

In conclusion

The choice of cast-iron radiators in the house is determined by the financial opportunity, the desire to be considered a connoisseur of antiquity / technical innovations, nostalgia or urgent need. The relative disadvantages will overlap the absolute durability of the product and the purity of its inner world. The design of the later models is so different from the previous ones that they will become a magnificent decoration of the room.

The video in this article shows the process of assembling a cast iron radiator.