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Both the A380 and 787 have higher internal cabin pressures (equivalent of 6000ft). All other planes operate at lower pressure. Anything above 6000ft leads to al

Both the A380 and 787 have higher internal cabin pressures (equivalent of 6000ft). All other planes operate at lower pressure. Anything above 6000ft leads to altitude sickness for those who live at ~0ft. https://www.usatoday.com/story/travel/columnist/hobica/2017/01/18/jet-lag-altitude-sickness-dehydration/96677564/ https://www.usatoday.com/story/travel/columnist/hobica/2017/...

brunnsbe 9y ago
You forgot the A350, which is also mentioned in the article.
InTheArena 9y ago
This is really good marketing but not really true. A recent study of pressurization found that 747s tend to be operated at lower pressurization the a380s (which are typically run a bit higher then their rates). Almost 1k feet IIRC. What makes a huge huge difference is humidity. I get off a Denver to narita 787 feeling like it was a long Colorado to California flight, whereas a SFO to Narita flight on a 380 or 747 wrecks me.
- Scoundreller 9y ago
  Given Denver's altitude of ~5000', the smaller take-off pressurization effect may be a (small?) factor. You're almost acclimatized to cabin pressure already. Denver's altitude also means a lower maximum takeoff weight. Perhaps less cargo/passengers = faster luggage / more empty seats?
- barbegal 9y ago
  The 787 air quality is better for two reasons: it has a higher humidity and it contains less VOCs. The reason for both of these factors is that the 787 is designed to take cabin air directly from the atmosphere rather than from a compressor bleed valve as in every other aircraft. This was a radical design decision for Boeing because bleed air usually has three key functions: it is hot enough to cause toxic ozone gas to decompose, it is at high pressure so can pressurise the cabin and it is hot so it can heat the cabin. Without bleed air Boeing had to do all these things with new components, they have an ozone filter/catalyst, an electrical compressor and a RAM heat exchanger to heat up the air (basically slows down the air increasing its temperature). The system is more complex but according to Boeing uses less energy [1] and makes servicing the engines easier. For passengers, external air contains more moisture than the bleed air (air becomes less humid if it is compressed and heated) so the inlet air humidity is around 7% compared to 2% on other planes. But this is still less than the humidity in a typical cabin which is about 10 to 20%. Some of this is residual moisture that is recirculated but most is from passenger respiration and transpiration [2]. Even so the higher inlet humidity coming in can significantly slow down the loss of moisture over a long flight. In addition VOCs and other bleed air contaminants are minimised [3] which Boeing claims means we feel better after a long flight. [1] http://www.boeing.com/commercial/aeromagazine/articles/qtr_4_07/AERO_Q407_article2.pdf http://www.boeing.com/commercial/aeromagazine/articles/qtr_4... [2] http://webserver.dmt.upm.es/~isidoro/tc3/Aircraft%20ECS.pdf http://webserver.dmt.upm.es/~isidoro/tc3/Aircraft%20ECS.pdf [3] https://www.faa.gov/data_research/research/med_humanfacs/oamtechreports/2010s/media/201520.pdf https://www.faa.gov/data_research/research/med_humanfacs/oam...

brunnsbe 9y ago

You forgot the A350, which is also mentioned in the article.

InTheArena 9y ago

This is really good marketing but not really true. A recent study of pressurization found that 747s tend to be operated at lower pressurization the a380s (which are typically run a bit higher then their rates). Almost 1k feet IIRC. What makes a huge huge difference is humidity. I get off a Denver to narita 787 feeling like it was a long Colorado to California flight, whereas a SFO to Narita flight on a 380 or 747 wrecks me.

Scoundreller 9y ago
Given Denver's altitude of ~5000', the smaller take-off pressurization effect may be a (small?) factor. You're almost acclimatized to cabin pressure already. Denver's altitude also means a lower maximum takeoff weight. Perhaps less cargo/passengers = faster luggage / more empty seats?
barbegal 9y ago
The 787 air quality is better for two reasons: it has a higher humidity and it contains less VOCs. The reason for both of these factors is that the 787 is designed to take cabin air directly from the atmosphere rather than from a compressor bleed valve as in every other aircraft. This was a radical design decision for Boeing because bleed air usually has three key functions: it is hot enough to cause toxic ozone gas to decompose, it is at high pressure so can pressurise the cabin and it is hot so it can heat the cabin. Without bleed air Boeing had to do all these things with new components, they have an ozone filter/catalyst, an electrical compressor and a RAM heat exchanger to heat up the air (basically slows down the air increasing its temperature). The system is more complex but according to Boeing uses less energy [1] and makes servicing the engines easier. For passengers, external air contains more moisture than the bleed air (air becomes less humid if it is compressed and heated) so the inlet air humidity is around 7% compared to 2% on other planes. But this is still less than the humidity in a typical cabin which is about 10 to 20%. Some of this is residual moisture that is recirculated but most is from passenger respiration and transpiration [2]. Even so the higher inlet humidity coming in can significantly slow down the loss of moisture over a long flight. In addition VOCs and other bleed air contaminants are minimised [3] which Boeing claims means we feel better after a long flight. [1] http://www.boeing.com/commercial/aeromagazine/articles/qtr_4_07/AERO_Q407_article2.pdf http://www.boeing.com/commercial/aeromagazine/articles/qtr_4... [2] http://webserver.dmt.upm.es/~isidoro/tc3/Aircraft%20ECS.pdf http://webserver.dmt.upm.es/~isidoro/tc3/Aircraft%20ECS.pdf [3] https://www.faa.gov/data_research/research/med_humanfacs/oamtechreports/2010s/media/201520.pdf https://www.faa.gov/data_research/research/med_humanfacs/oam...