According to the relevant regulations and standards, the chimneys should be able to maintain their resistance against any fire hazard for at least 90 minutes. One function of the chimneys is to prevent the spread of a fire occurring somewhere in the building to the other floors. The chimney outer surface must therefore be made of a fire-resistant material and the chimneys through which exhaust gases pass through must be resistant to high temperatures and temperature changes. At the flue gas temperature of 5000 degrees, the surface temperature of the chimneys must not exceed 100 degrees. If there is a fire in the chimney due to soot build-up, the chimney gas temperature increases to one thousand degrees and the outside temperature reaches 160.

Chimney connection directly affects the performance of the boilers. In order for accidents to work efficiently and properly, the correct chimney cross section must be determined and the correct chimney connection must be made. During installation, boiler capacity, type of fuel used, effective flue height and flue outlet temperature should be considered.

The exhaust gas temperature and the chimney inner surface temperature fall towards the upper parts of the chimney. If the temperature drop is too high and falls below the limit values, condensation starts. In this case the traction of the chimney decreases and in time the chimney becomes unable to function. Temperature changes inside the chimneys without thermal insulation cause condensation.

For these reasons, determination of gas temperature is important. The exhaust gas temperature must be higher than the outside air temperature. However, in this case, there is no condensation in the chimney and the chimney does its job in a healthy way.

Laboratories that determine gas temperature within the scope of emission measurements should have obtained Environmental Analysis Qualification and Environmental Analysis Prequalification Certificate from the Ministry of Environment and Forestry. It is also important that the laboratories providing this service are experienced and show strong references.