In the article here : https://abcnews.go.com/Health/Healthday/story?id=4507808&page=1 it is claimed that
Short-haul flights are usually pressurized at 5,000 to 6,000 feet while long-haul flights are closer to 8,000 feet, according to Thibeault, [M.D., medical advisor, IATA].
But why would this be? My understanding is that the cabin pressure is chosen as a balance of:
- what the aircraft can withstand without slow structural deformations, so that it is functional for many years
- what is most comfortable for the passengers
- most fuel efficient- pumping in air requires some fuel.
With regards to comfort, I should think that low pressures take their toll after a few hours (I think I read 3-9 hours, for people developing altitude sickness symptoms at about 8500ft equivalent cabin pressure).
The only guesses I have at why short-haul flights can operate at higher cabin pressure is:
the aircraft body won't have as much structural change with a short-term pressure difference
the plane can 'retain in' air pressure without actively pumping it for some time on the order of hours/ half-hours, so it is not so energetically costly.