Retrofitting London buses with decent aircon

speedy1 · 10 Jul 2026

Is it feasible?

Does the fare-payer want to pay for it?

Sorry for the Chatgpt estimate but I've got a sinus infection (probably from aircon in London :lol:

):

Back-of-the-envelope estimate

Assumptions:

Fleet size: 8,700 buses

Retrofit cost: £60,000 per bus

Total capital cost = 8,700 × £60,000 = £522 million

Finance over 10 years at ~5% ≈ £68 million/year

Additional electricity, maintenance and repairs = £30–60 million/year

Total annual cost:

£68m + £30–60m = £98–128 million/year

Assuming 1.9 billion bus journeys per year:

£98–128m ÷ 1.9bn = 5.2–6.7p per journey

However lots of those journeys are probably free, so let's be conservative and 3x it to 15p-21p increase on fares.

Anyone got a better estimate?

RailUK Forums

SynthD · 10 Jul 2026

Lock the windows shut on relevant days and see what difference that makes before spending any money. It’ll be easier to say what’s worth adding to fares after that.

Edit: upon re reading this I don’t know what I was saying. Was I thinking of people opening windows on buses cooled with AC?

Anonymous10 · 10 Jul 2026

SynthD said:
Lock the windows shut on relevant days and see what difference that makes before spending any money. It’ll be easier to say what’s worth adding to fares after that.

Id take having aircon on my buses here in west wales. Well in excess of 30 degrees.

Nicholas Lewis · 10 Jul 2026

SynthD said:
Lock the windows shut on relevant days and see what difference that makes before spending any money. It’ll be easier to say what’s worth adding to fares after that.

I was on non air con London Double Decker yesterday which had even less opening windows than a Networker and it was awful. I stayed downstairs which was bad enough but must have been unusable upstairs. All the driver has is a bigger window to help and mediocre fan which is very poor working conditions so they need to do something for them.

speedy1 · 10 Jul 2026

SynthD said:
Lock the windows shut on relevant days and see what difference that makes before spending any money. It’ll be easier to say what’s worth adding to fares after that.

Interesting theory. Isn't that the last step after fitting anti solar films on the window, high quality insulation, having smaller windows, painting the entire bus white or other similar anti solar paint, etc, because heat doesn't just come in through the air? Not forgetting some kind of mechanical ventilation that attempts to reduce the incoming heat, because you can't just suffocate passengers.

How much of that already exists on London buses?

== Doublepost prevention - post automatically merged: 10 Jul 2026 ==

Nicholas Lewis said:
I was on non air con London Double Decker yesterday which had even less opening windows than a Networker and it was awful. I stayed downstairs which was bad enough but must have been unusable upstairs.

I was upstairs on one a couple of days ago and I wish I had a thermometer with me. It must have been 40c. It's the only time in my life that the phrase "like a sauna in here" applied so literally.

JonathanH · 10 Jul 2026

Isn't there a challenge with the weight limits that precludes features on double deck buses that are prevalent on single deckers. I recall that certain features of the 'Barbie' specification on single deck Wright Renowns like double glazing and airflow couldn't be installed in double deck buses otherwise to the same broad specification.

Mgameing123 · 10 Jul 2026

JonathanH said:
Isn't there a challenge with the weight limits that precludes features on double deck buses that are prevalent on single deckers. I recall that certain features of the 'Barbie' specification on single deck Wright Renowns like double glazing and airflow couldn't be installed in double deck buses otherwise to the same broad specification.

Surely that can be solved by using tri axles.

Nicholas Lewis · 10 Jul 2026

JonathanH said:
Isn't there a challenge with the weight limits that precludes features on double deck buses that are prevalent on single deckers. I recall that certain features of the 'Barbie' specification on single deck Wright Renowns like double glazing and airflow couldn't be installed in double deck buses otherwise to the same broad specification.

They have air cooling on some DDs which at least keeps temps below 30 deg C

speedy1 · 10 Jul 2026

I'm particularly curious about the costs and requirements of getting it done, rather than reasons why it can't. :lol:

Or even more crazy, replace the entire fleet? 8,700 x £400,000 for a bunch of new electric BYDs. How does TfL finance £3.5bn of capex? Raise fares to £2.50? Scrap some free bus journeys?

Nicholas Lewis · 10 Jul 2026

speedy1 said:
I'm particularly curious about the costs and requirements of getting it done, rather than reasons why it can't.

Or even more crazy, replace the entire fleet? 8,700 x £400,000 for a bunch of new electric BYDs. How does TfL finance £3.5bn of capex? Raise fares to £2.50? Scrap some free bus journeys?

It gets the bus operator to buy them and that is reflected in the cost of delivering the service on each route

SLC001 · 22 Jul 2026

During the recent heatwave, the temperature in the cabs of London buses reached 40 degrees. Drivers were taking thermometers in to measure it. I know of 2 incidents where there were minor crashes as a result of the driver being too hot. I believe that in one case the driver lost his job and is now considering his legal options. There is air conditioning. It doesn't work. Ask for an exchange bus and you get the the same outcome. The air conditioning doesn't work.
2 minor shunts that I know of. How long before we have a serious injury? We cannot afford not to have effective air conditioning in the cab.

Retrofitting London buses with decent aircon

speedy1

Member

RailUK Forums

SynthD

Established Member

Anonymous10

Established Member

Nicholas Lewis

Established Member

speedy1

Member

JonathanH

Veteran Member

Mgameing123

Member

Nicholas Lewis

Established Member

speedy1

Member

Nicholas Lewis

Established Member

SLC001

Member