If your local chimney sweep requests a calculation and you don't have it done, you won't receive a permit to operate the system, and your stove will literally stay cold. If you continue heating, you'll be left with the costs in the event of damage, as insurance only pays if everything has been properly inspected. More importantly, you're endangering your own health and that of your family! Even if you receive the fireplace inspection certificate without a calculation, it may still be advisable to have it done.

Not every fireplace can be connected to every chimney, and unsuitable combinations, cross-sections that are too small or too large, effective heights that are too small or too large, and other factors can lead to operational disruptions. The chimney either has no draft or too little draft, and instead of escaping over the roof, the smoke ends up in your living room. Or the chimney draft is far too strong, and you can't keep up with adding wood, and it still doesn't get properly warm because all the heat disappears up the stovepipe. Often, such problems can be identified in advance through a chimney calculation and avoided by selecting a suitable fireplace or properly designing the exhaust system.

For existing systems, it can be determined whether additional components such as throttle valves or chimney fans could improve functionality. Even if other fireplaces are already connected to the same chimney (for example, in an apartment building), or you would at least like to have the option of connecting multiple fireplaces, the calculation provides reliable information about the feasibility of your project and the measures required for implementation.
Who can calculate the cross-sectional area of ​​my chimney?

In principle, any local chimney sweep should be able to perform this, and some chimney and fireplace suppliers also offer this service. Since many factors must be considered and a considerable amount of experience is required to perform the calculation correctly, you should always leave it to a specialist. They usually have professional software solutions at their disposal.