We tested a system for sealing air ducts

In cooperation with Alkion service, an experiment was carried out in the test hall of the CTU UCEEB in Bustehrad to measure the effect of the application of the AEROSEAL system on the tightness of air ducts. Using the PIV anemometry method, it was possible to demonstrate a significant increase in tightness in a very short time.

For the purpose of the measurements, we created a model air duct network consisting mainly of square ducts with dimensions ranging from 700 x 600 mm to 250 x 300 mm. The total area of the duct network exceeded 70 m2. Its tightness was determined according to the standard CSN EN 1507 and the newer CSN EN 16798-3.

The first measurement was taken prior to the sealing of the model duct network, which was subsequently carried out by Alkion service. Using an automated sealing device, they injected an aerosol under pressure into it, which pooled at the leak points and formed a permanently elastic sealant. The second measurement was started at the beginning of the sealing process and ended when the leak was closed in the form of a 4 mm diameter hole in the duct wall.

For the measurements, we used the PIV anemometry method, which is based on camera tracking of the movement of tracer particles scattered in the measurement medium illuminated by a pulsed laser. Using this method, we were able to prove that within minutes of aerosol application, the leak rate of the duct dropped by up to 96 % at positive pressure and up to 92 % at negative pressure. This also allowed the duct to meet the significantly more stringent leak class requirements of the standards.