The main purpose of the London Underground's ventilation fans is to extract hot air from the tunnels, and fans across the network are being refurbished, although complaints of noise from local residents preclude their use at full power at night.
Hovedformålet ved ventilatorerne i London Underground er at udlede var luft fra tunnellerne, og netværkets ventilatorer er blevet renoveret, selvom støjklager fra naboer udelukker brug ved fuld kraft om aftenen.