Why Don’t AGT Cars Have Air Conditioners on the Roof?

If you look at the roof of a commuter

train, you’ll often see large, box-

shaped air conditioners sitting on top.

Anyone who rides trains regularly has

probably noticed them.

But if you glance up at an Automated

Guideway Transit (AGT) vehicle, you

won’t see those units. The roof is

perfectly flat and simple in design.

So where, exactly, are the air

conditioners hiding?

The answer lies in a “distributed

layout.” Just like a home air

conditioner has both an indoor unit

and an outdoor unit, AGT cars also

split their system: the indoor units are

tucked above the ceiling, while the

outdoor units are installed beneath the

floor. That’s why nothing is visible

on the roof.

So why not mount them on top, like

in conventional trains? The reason

comes from the Ministry of Land,

Infrastructure, Transport and

Tourism’s “Basic Specifications for

New Transit Systems.” These rules

limit AGT vehicles to a maximum

height of 3.3 meters. With such a

restriction, there’s no space to add

bulky equipment above.

Instead, designers prioritize passenger

comfort by keeping the ceiling as

high as possible within that limit. The

result is the clean, flat roofline that

characterizes AGT vehicles. What may

seem like a simple design choice

actually reflects a thoughtful effort to

make the ride feel more spacious and

comfortable.

Stay tuned for the next AGT Blog!