Five of those trains have been approved and are running on the CityTrain network. “We have been getting some feedback and complaints for quite a while,” Mr Dow said. “People are saying that it is just hot and humid inside the new trains. It has come up enough times now and for long enough for us to think this could be a bad problem. “We think the temperature needs to be turned down a few degrees.” Commuters seem to agree.

Damian Jones posted on Rail Back on Track's website that the airconditioning in the new trains could not handle Queensland’s heat. “Another air-con system from overseas that can't handle Queensland’s humidity and high temperatures,” he posted. Another commuter, Imran Isawi, agreed. “Why can’t QR have decent, reliable (airconditioning) when other states can?" he asked. “Sydney’s trains put ours to shame. Queensland is sub-tropical, mostly warm to hot and frequently humid. Proper air-con is just a basic necessity on public transport.

"You see business professionals in, or others, in collar and tie/uniforms, running to the platform to catch a train that isn’t even there yet. Then get on board and it’s stuffy and sweaty.” Others said the airconditioning temperatures in the new trains varied between carriages. A TransLink spokesman confirmed a trial to improve airconditioning on the new trains had started. "The New Generation Rollingstock project team has taken note of feedback from some customers regarding the temperature of the airconditioning system in the NGR trains, and is actively investigating the issue," he said.

"A trial is under way which involves a slight lowering of the airconditioning temperature, which includes a detailed analysis of the temperature across the carriages to ensure customer comfort. "Early feedback from this trial has been positive. If this adjustment to the temperature resolves the issue, it will be made on all NGR trains in passenger service by the end of this week." The TransLink spokesman said the airconditioning issue was not stopping the new trains from being added to service. "This issue is not a fault with the units and is not affecting the introduction of new trains into service," he said. Queensland Rail hopes to have between 10 and 15 new trains in place by the Commonwealth Games in April. Overall, 75 new trains have been ordered.

Problems with the airconditioning on the Indian-built trains was one issue identified in March 2017, when delivery of the new trains was halted. Mr Dow said the airconditioning in the new trains contrasted with the rest of the trains in south-east Queensland’s train fleet, nicknamed EMUs, which stands for electrical multiple units. “The EMUs, which the NGR trains are destined to replace, have, in our opinion, the best airconditioning of the entire train fleet,” Mr Dow posted. “There is a marked difference between the cool environment on an EMU, compared to the hot, humid environment on a NGR train.” Commuters say the airconditioning in Queensland's new trains leaves the carriages 'hot and humid'.

One comment suggested airconditioning problems were delaying QR’s formal acceptance of the NGR trains. This was denied by Queensland Rail’s TransLink. Mr Dow said he travelled on one of the new trains to test the airconditioning after hearing complaints. “It seems to be variable,” he said. “It seems to vary from carriage to carriage and it depends on where you sit in the carriage but, as I say, it is coming up enough times now to suggest this could be bad problem.”