Condensation boiler: pros and cons

Everyone who is faced with the need to heat a private or country house, cottage or other building with individual heating wants to achieve maximum efficiency and efficiency from the heating device. It is this desire of consumers that makes manufacturers of such equipment constantly look for new solutions and improve their products. For example, a condensing boiler was developed. In this article we look at the pros and cons of condensing boilers, as well as the principle of operation.

Condensing boiler - what is it?

All specialists in the field of heat engineering and heating equipment have long known that the combustion of gas into the atmosphere leaves the products of its combustion, which have a high enough temperature - up to 160 ° C. This is the heat that could go to heat the coolant, but in ordinary gas boilers it is "lost". The condensation process can make it useful. Specialists have also known about this for a long time, therefore, a technology has been developed for the production of condensation boilers, which additionally heat the water returning to the boiler.

"Highlight" new boilers

Condensation boiler looks no different from an ordinary gas boiler. All its advantages and differences are hidden under the shell. The biggest difference and advantage is that the gases formed after combustion of the fuel do not go directly into the atmosphere, but pass through a condensing heat exchanger. This node of the boiler has the shape of a pipe with a complex ribbed surface. In this way, the heat exchange area increases. A pipe passes around the condensation unit and returns water to the boiler. On the way to the burners, the "return" is additionally heated by the outgoing gases.

Giving its heat, the gases are cooled to 40 ° C, and the water contained in them from the vapor turns into a liquid. The cooling temperature is significantly lower than the one at which condensate begins to form. In other words, it is below the “dew point”, which is 55 ° C.

Condensate flows into a special tank, and then into the sewer. The cooled gases with a temperature of 10–15 ° C above the “return” temperature are emitted into the atmosphere, but this is no longer 160 ° C. At the same time, the “return” reaches the place of the main heating with a higher temperature and less fuel is required to bring it to the set temperature. Designers of boilers, applying a similar principle of operation, have achieved maximum efficiency and equipment efficiency. Firstly, fuel economy reaches 20%. Secondly, such equipment is highly environmentally friendly by reducing the concentration of carbon dioxide and other harmful substances in the emissions.

Characteristics of the equipment

Despite the fact that the principle of heat extraction due to condensation was known for a long time, it was impossible to apply it in steel and cast iron boilers. The thing is that the resulting liquid has a high acidity. Therefore, the material from which heat exchangers are made in such boilers requires certain technical characteristics: it must be resistant to corrosion and chemical attack. Stainless steel and aluminum-silicon alloy (silumin) are perfect for this purpose.

The advantages of these heaters include:

• Compact size, low vibration, silent operation. Due to this, for the installation of such equipment does not require special premises.
• Fuel economy. Additional heating of the coolant, equipment for regulating the supply of gas-air mixture, depending on the required load.
• Environmental friendliness. Leaving gases of lower temperature and concentration do less harm to the environment.
• Saving on the tube. Since the boiler has a fan in the design, sucking the fuel out of the gas pipeline to mix gas and air, and a pump that optimizes the power of the boiler and is regulated by electronics, it is possible that the diameter of the pipe may be narrowed twice. In addition, the low flue gas temperature allows the use of heat-resistant plastic as a material for a pipe;
• no need to warm the pipe to avoid condensation, as is done when installing conventional boilers;
• Cascade installation of condensation boilers in boiler rooms is possible. This scheme is used mainly in the roof boiler.

The disadvantages of such heating devices can be attributed, perhaps, only their high cost. It is two times higher than the price of an ordinary gas boiler.

Scope and type of boilers

Modern condensing boilers are new, perhaps, only in our country. In Europe, they have long been concerned about the environment, saving energy and money with the help of such equipment. They even developed sanitary rules for the use of boilers. Since condensate has a high acidity, its direct entry into the sewer system is unacceptable. You must first pass it through an alkaline medium and dispose of neutral water into the sewer system.

Coppers are issued hinged and floor. The first have a power of up to twenty kilowatts and are mainly used for domestic purposes. The latter have much more power and are installed in boiler rooms. Also, condensing boilers can provide not only heat but also hot water.

A specialist will tell you how to choose the boiler you need. Basically, the choice of heating equipment is based on what area it is able to heat and how many liters of hot water can give per second, i.e. on its performance.

Video: condensing boiler operation principle

This video is about replacing an old boiler with a condensing boiler. You will learn what the effect is and hear the opinion of the owners of the house: