For many years now, the SMC has been producing standard or specific casing for elevated ventilation shafts in parking places or extraction shafts in professional kitchens.

Conversion of shunt shafts
Natural ventilation in VMC (controlled mechanical ventilation)

The SMC carries out this type of work by means of providing and installing passages and extractor fans as well as the fitting in of appropriate air vents inside the apartments.

Control of shunt shafts

Nothing differentiates a watertight shaft from one which is not. The traditional test involves the use of a smoke-producing device, the procedure of which is long and expensive, and the observations resulting from this test are empirical. If a shaft leaks, it is impossible to gauge the flow of the leak. Moreover, the leak would be located in a compartment which was designed to be watertight. The individual shafts are not well-controlled. The smoke coming out of the cartridges installed in the exhaust manifold does not come out properly from the individual shafts.

In conclusion, the test using a smoke-producing device does not respond to the specific criteria required for the conversion of shunt shafts. The rate of the leak from the reused vertical shafts must not exceed 5% of the flow extracted..
The SMC has developed a measuring apparatus which puts the shaft to be verified at a pressure level that is equivalent to 150 Pa, the volume of air to be extracted after the sealing of all the entry vents by watertight sheets. This is measured by means of a flowmeter. It indicates the rate of the leak from the shaft under its new conditions of utilization.

For their conversion into vertical shafts for VMC, the individual shafts are not necessary. Only the exhaust manifolds remain usable because the casing of the individual shafts is very delicate and difficult to make .

With the help of robots designed and created by the SMC, the procedure is carried out by means of installing sealing plates in the intercommunicating portions between the individual shafts and the manilfolds at different levels.