Graham Murray wrote:
Roland Perry writes:

In message , at 13:50:29 on Sat, 30 Jul
2016, " remarked:

Are they ever going to figure out air conditioning for Tube trains?

Pump the heat out of the trains into the tunnels and stations. What
could possibly go wrong?

And equip alternate stations with powerful air conditioners and
extractor fans, creating a cooling airflow along the tunnels.

Some of that is already in place. Ventilation has been significantly
improved in many stations, and I think some use heat exchangers to cool the
air using pumped ground water.

As for the trains, the NTfL is intended to incorporate saloon cooling, as
well as emitting less heat in the first place. See page 24 in
http://content.tfl.gov.uk/ntfl-feasibility-report.pdf