(05 Sep 2020, 10:35 am)Storx wrote God knows, believe it's just like a car heating system though when you have no aircon, I know the Gemini's at Blyth do it aswell as they can blow cold air out aswell from the heating system but I believe it just recycles air around the bus from the vents under the backseats (you can definitely feel them sucking air in on the Gemini's at Blyth first thing in the morning as it's freezing cold since the engine is still cold).
The Streetdecks still appear to have them so assume it's still done like that - https://pbs.twimg.com/media/ED4azWOXoAMGsOQ?format=jpg&name=large
During the heatwave last year, it was legit ice cold on the StreetDecks, even when I got on from Tindale in the afternoon, so they would have been running for a number of hours