In almost every settlement, despite the level of its gasification, there are houses with brick-built chimneys installed on the roofs. And they would have stood for decades, but only after connecting and starting the boiler, they begin to crumble - the brick crumbles and collapses. What is the reason for such metamorphoses? It turns out there are a few points and some difference between a standard wood-burning fireplace (or stove) and a modern boiler.
1. What is the difference
The boiler, when compared with a stove heating system, has a fairly high efficiency. It is not difficult to calculate it. The fuel that is sent to it at the input is 100%, while at the output we get heat, heating the house, and combustion products. Efficiency is the difference between what is placed in the boiler and emitted into the chimney (chimney). The percentage of heat that leaves the building through the chimney is deducted from 100%. As a result, we get the efficiency of the heating device.
The high efficiency rates of the boiler are associated with too low recoil temperature of the very same combustion products - from 90 to 96 percent. The less heat energy is released into the air, the warmer it is in the building. The exhaust temperature of gas boilers does not exceed two hundred degrees Celsius, and fireplaces - up to 500-700 degrees. Some believe that, taking into account the basic characteristics of the boiler plant, the pipe will be in good condition for a longer period. In reality, everything is exactly the opposite.
2. What is the problem
Two heating sources are connected to one pipe. As a result, the condensate in the mine will concentrate not in one place, but in different places (dew point formation). When the furnace is operating, due to the fact that the temperature is very high, this point is outside the pipe, which means that the latter will remain dry almost always. When the boiler is operating, + 200 ° C is not enough for the condensate to be carried out of the pipe. Basically, it is collected in a place located between the roof and the outlet (hole) of the combustion products.
It turns out that in the case of stove heating, only soot remains on the walls of the pipe, and in the case of a boiler, moisture. The boiler operates cyclically - on / off. This happens several dozen times during the day. As a result, in winter, wet brick is frozen and thawed many times, which has an extremely negative effect on its characteristics and structure. After a couple of seasons, it simply begins to crumble.
In order to prevent the destruction of the chimney, it must be insulated from the outside, and also cased using stainless steel. When installing a gas boiler, it is always necessary to modernize the chimney.
It will be no less interesting and useful to find out why stoves "potbelly stove" and "Dutch woman" bear such strange names.