The Engima Cipher Center is a facility with an interactive multimedia exhibition dedicated to the Enigma cipher machine and three Polish cryptologists: Marian Rejewski, Henryk Zygalski and Jerzy Różycki, located in the building of the former Collegium Historicum, currently Collegium Martineum, at the corner of Saint Marcin and Tadeusz Kościuszko streets in Poznań. Originally, the building served as the headquarters of the Provincial Committee of the Polish United Workers' Party, then the building served the University of Adam Mickiewicz. The works performed by Energy Air included sealing the installations on the first floor of the building. Leakage measurements and sealing using AEROSEAL® technology included: • N1 ventilation duct; • W2 ventilation duct. After completing the work, the leakage value of the tested system does not exceed the limit value of tightness class B.