TfL are trialling cooling solutions at a disused platform at Holborn, that could be used on the deepest tube lines on the Bakerloo, Central, Jubilee, Northern, Piccadilly, Victoria and Waterloo & City lines to significantly reduce temperatures. The cooling panel will aim to deliver cooler air to passengers waiting on platforms.
Following the trial at Holborn station and subject to funding being available, TfL will explore whether the panels could provide a cooling solution for other deep Tube lines in the future. Further testing would need to take place in a station open to customers (Knightsbridge) before TfL could look to potentially introduce them at four additional stations on the Piccadilly line (Green Park, Holborn, Leicester Square and Piccadilly Circus). TfL could then identify other locations where the panels could provide a benefit. Progressing this trial at other locations would ultimately be subject to TfL having sufficient long-term capital funding available.
Piccadilly Line will soon have new air-conditioned trains on the line, from 2025, to slowly phase out older carriages. The amount of trains per hour will be increased, producing more heat, so the cooling trial will be rolled out first on this line.