Spektrum Tower is a modernist office skyscraper located in Śródmieście at 18 Twarda Street in Warsaw, near the Central Railway Station. It is the former headquarters of Telekomunikacja Polska (until 2018). A unique feature of the building is the external, panoramic elevator, which runs at a speed of 2.5 m/s in a shaft tilted by 14° from the vertical. There is a helicopter landing pad on the roof of the building. Energy Air's work included sealing the supply ducts in the office space, performed by mountaineers in the following installations: NA-2 – floors from -1 to +7 - leakage reduction 97.7%; NB-2 – floors from +8 to +29 - leakage reduction 96.7%. The installations meet the standards of tightness class B.